Well mine will be different from most here as I see the spiritual path as most important - not in sense of organized religion necessarily - but in sense that human happiness is what matters far more than worldly success.
So, first, to learn to be content with whatever you have. All humans need to survive is food (including water and air obviously), shelter and clothing. Anything else is luxury.
If you are content with what you have then you may be a bit less likely to end up a millionaire, but you will have a happier life. And if you do become a wealthy person - is no reason why not, you'll be a more happy, fullfilled and productive wealthy person.
And to be generous also in small ways - not over the top., but if you have a tendency towards miserliness to see if you can do something about that, And if one has the wish to help others so much the better.
As for health, many people need a fair bit of exercise, some less so and if you have e.g. ME then you may need to be careful even with what most would consider light exercise.
So find out what your body needs and an enjoyable activity that helps you stay fit. I found that I need lots of exercise, and for me the exercise was hill walking. Some may get plenty of exercise already as part of their work, but if not, well that's something to pay a bit of attention to I think by age 30.
Plus obviously things like if you are a habitual smoker, is a benefit to your health if you can stop but others here have given plenty of good answers on health so won't say any more.
And - to find out what is the right path for you. Others may have different paths - that doesn't mean they are right and you are wrong or vice versa. We all need different paths in our lives.
For some your path may be setting up a business, the next Virgin Galactica. For others may be studying, and proving new results in maths or science, or scientific experiments.
For others may be to build houses. Or become a plumber. Or to drive a train.
Or to be a chef, or a composer, or an artist, or a gardener.
Whatever your dream is, to find out what it is and follow it.
And there is nothing wrong with an "ordinary" life. If you are a gardener, you don't have to be a world class gardener or create a garden that people flock from miles around to see.
Some people in the West think that we should all be celebrities, not just acting celebrities, - but - in some way the goal of life is to be a celebrity in whatever is your chosen sphere. To be widely known, e.g. as a mathematician at least amongst mathematicians - or as a gardener, at least amongst other gardeners.
But celebrities though they may seem to have all the glamour and wealth and things we wold like - they have many problems also. It is not the end of all your problems to be a celebrity.
And as well as that - it's obviously not a practical possibility either, with billions of people - if we all aim to be celebrities then most of us will be disatisfied when we don't become one. And the few that do become celebrities are also unhappy quite often.
While if you can learn to be content with whatever your situation is, you can be one of the few genuinely happy people in our society :).
And - in the West I think n your 30s is a time when you may begin to appreciate your parents once more after what is often a somewhat rebellious phase in your teens or twenties.
They are the ones who brought you up. And they also have similar DNA, and they have a lot of wisdom which you can learn from. Not necessarily to follow the way they do things. But you can learn also from their mistakes too. And - when the children leave home, it's a tough time for parents also. Maybe you can do things to help them. Visiting them more often for instance. Especially if they have few children.
Same also for your siblings if you have any.
Some Westerners don't even see their parents from one year to the next.
May be special cases of course where that is appropriate, e.g. if you were abused as a child, you could be justifiably scared of returning home and it might be quite right to keep a distance. Even then - people change, can change, it might be that you can find a way to help them find a new direction in their lives, and turn away from their mistakes.
But in most cases, it is just laziness and not really appreciating your parents and you have other things that interest you. So I think if you can find a way to make a connection with them, and - you may find some things in common with them., more than you expect. Some interest you share, or some way of connecting to them.
Because we are not a traditional society chances are you've come across ideas and changed in ways that mean you don't see eye to eye with them on many issues. But then - that's part of what a family can help with - to learn to get along with people you don't agree with on many issues.
I come from a family which is very argumentative. If you didn't understand the situation you might at times think we hate each other. But it isn't like that at all. Rather, we free to speak our minds because the family ties are so strong.
And later in your life they may become ill and old and need your help.
Of course here I'll get readers from many different traditions and backgrounds, so that is mainly for Westerners who have a tendency towards completely dissociating ourselves from our parents, some of us. So if you are in that sort of a situation, well in the 30s is quite a good age to re-evaluate, take a broader perspective - and may perhaps be a good time to do some rebuilding of ties with them.
I'm a Buddhist myself, but not at all in the sense that I think that anyone else needs to be Buddhist.
Here Ringu Tulku who talks about Buddhist ideas with simplicity and clarity. He is a proponent of the Rime movement - "no boundaries" - that the Buddha said he taught many different methods for different people - can't say one is right or wrong or higher or lower. I don't know anything about him except that I found his video teachings on the internet the other day, and they made an impression on me, I think he has something useful to say to our modern world.
Listen to what he says about the Tibetan Rime "no boundaries" movement (towards the end), and his suggestion that that same approach can be brought to the whole world, many paths, prophets, religious, non religious. and so on. And how differences are something good.
So - I think at age 30 is a good time to reflect on the path you find yourself on. And possibly look for other paths if you aren't satisfied with the path you are following whatever it is - spiritual, academic, business or whatever.
That's about the age at which I found the Buddha's teachings myself, well a little bit before.
I'm not at all saying this has to be a spiritual path in conventional sense. So could be path towards becoming a good gardener or a good business person or academic or whatever.
Just finding what direction you are going, and think about exploring other possibilities, if you are not so sure about the direction. Don't need to follow them, just find out about them, might well decide whatever you are doing is the right path for you anyway. But to be aware of other possibilities. I think is a good time for that also.
And what is the right path for others may not always be the path for you. Different is good!
CONTENT WITH WHAT YOU HAVE
So, first, to learn to be content with whatever you have. All humans need to survive is food (including water and air obviously), shelter and clothing. Anything else is luxury.
If you are content with what you have then you may be a bit less likely to end up a millionaire, but you will have a happier life. And if you do become a wealthy person - is no reason why not, you'll be a more happy, fullfilled and productive wealthy person.
And to be generous also in small ways - not over the top., but if you have a tendency towards miserliness to see if you can do something about that, And if one has the wish to help others so much the better.
HEALTH
As for health, many people need a fair bit of exercise, some less so and if you have e.g. ME then you may need to be careful even with what most would consider light exercise.
So find out what your body needs and an enjoyable activity that helps you stay fit. I found that I need lots of exercise, and for me the exercise was hill walking. Some may get plenty of exercise already as part of their work, but if not, well that's something to pay a bit of attention to I think by age 30.
Plus obviously things like if you are a habitual smoker, is a benefit to your health if you can stop but others here have given plenty of good answers on health so won't say any more.
TO FIND YOUR PATH
And - to find out what is the right path for you. Others may have different paths - that doesn't mean they are right and you are wrong or vice versa. We all need different paths in our lives.
For some your path may be setting up a business, the next Virgin Galactica. For others may be studying, and proving new results in maths or science, or scientific experiments.
For others may be to build houses. Or become a plumber. Or to drive a train.
Or to be a chef, or a composer, or an artist, or a gardener.
Whatever your dream is, to find out what it is and follow it.
ORDINARY LIFE OKAY NO NEED TO BECOME A CELEBRITY IN YOUR CHOSEN PATH OF LIFE
And there is nothing wrong with an "ordinary" life. If you are a gardener, you don't have to be a world class gardener or create a garden that people flock from miles around to see.
Some people in the West think that we should all be celebrities, not just acting celebrities, - but - in some way the goal of life is to be a celebrity in whatever is your chosen sphere. To be widely known, e.g. as a mathematician at least amongst mathematicians - or as a gardener, at least amongst other gardeners.
But celebrities though they may seem to have all the glamour and wealth and things we wold like - they have many problems also. It is not the end of all your problems to be a celebrity.
And as well as that - it's obviously not a practical possibility either, with billions of people - if we all aim to be celebrities then most of us will be disatisfied when we don't become one. And the few that do become celebrities are also unhappy quite often.
While if you can learn to be content with whatever your situation is, you can be one of the few genuinely happy people in our society :).
APPRECIATE YOUR PARENTS AND SIBLINGS
And - in the West I think n your 30s is a time when you may begin to appreciate your parents once more after what is often a somewhat rebellious phase in your teens or twenties.
They are the ones who brought you up. And they also have similar DNA, and they have a lot of wisdom which you can learn from. Not necessarily to follow the way they do things. But you can learn also from their mistakes too. And - when the children leave home, it's a tough time for parents also. Maybe you can do things to help them. Visiting them more often for instance. Especially if they have few children.
Same also for your siblings if you have any.
Some Westerners don't even see their parents from one year to the next.
May be special cases of course where that is appropriate, e.g. if you were abused as a child, you could be justifiably scared of returning home and it might be quite right to keep a distance. Even then - people change, can change, it might be that you can find a way to help them find a new direction in their lives, and turn away from their mistakes.
But in most cases, it is just laziness and not really appreciating your parents and you have other things that interest you. So I think if you can find a way to make a connection with them, and - you may find some things in common with them., more than you expect. Some interest you share, or some way of connecting to them.
Because we are not a traditional society chances are you've come across ideas and changed in ways that mean you don't see eye to eye with them on many issues. But then - that's part of what a family can help with - to learn to get along with people you don't agree with on many issues.
I come from a family which is very argumentative. If you didn't understand the situation you might at times think we hate each other. But it isn't like that at all. Rather, we free to speak our minds because the family ties are so strong.
And later in your life they may become ill and old and need your help.
Of course here I'll get readers from many different traditions and backgrounds, so that is mainly for Westerners who have a tendency towards completely dissociating ourselves from our parents, some of us. So if you are in that sort of a situation, well in the 30s is quite a good age to re-evaluate, take a broader perspective - and may perhaps be a good time to do some rebuilding of ties with them.
REFLECT ON THE PATH YOU ARE ON AND LOOK INTO OTHER WAYS
I'm a Buddhist myself, but not at all in the sense that I think that anyone else needs to be Buddhist.
Here Ringu Tulku who talks about Buddhist ideas with simplicity and clarity. He is a proponent of the Rime movement - "no boundaries" - that the Buddha said he taught many different methods for different people - can't say one is right or wrong or higher or lower. I don't know anything about him except that I found his video teachings on the internet the other day, and they made an impression on me, I think he has something useful to say to our modern world.
Listen to what he says about the Tibetan Rime "no boundaries" movement (towards the end), and his suggestion that that same approach can be brought to the whole world, many paths, prophets, religious, non religious. and so on. And how differences are something good.
So - I think at age 30 is a good time to reflect on the path you find yourself on. And possibly look for other paths if you aren't satisfied with the path you are following whatever it is - spiritual, academic, business or whatever.
That's about the age at which I found the Buddha's teachings myself, well a little bit before.
I'm not at all saying this has to be a spiritual path in conventional sense. So could be path towards becoming a good gardener or a good business person or academic or whatever.
Just finding what direction you are going, and think about exploring other possibilities, if you are not so sure about the direction. Don't need to follow them, just find out about them, might well decide whatever you are doing is the right path for you anyway. But to be aware of other possibilities. I think is a good time for that also.
And what is the right path for others may not always be the path for you. Different is good!
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
4.8m answer views110.4k this month
Top Writer2017, 2016, and 2015
Published WriterHuffPost, Slate, and 4 moreHuffPost, Slate, Forbes, Newsweek, Business Insider, and Science 2.0