Old guy here.

You're going to live into your 80s or 90s, thanks to modern medicine.

Plan for a lifetime of happiness and success, rather than a weekend. Don't let a bad year or two get you down.

Never think someone else can make you happy. Only you can own that. Giving that away to a spouse or friends will only leave you disappointed in yourself and them.

Your parents, your teachers, your religious leaders, your politicians and your friends might have some helpful advice, but only you can write the rules that you will live by. Make sure you have a clear set of values for yourself.

And take care of your health. The last thing you need is some witch of a nurse "caring" for you in an assisted living home. She's got decades of spite built up to take out on you. Be healthy enough in your old age to die in your own bed.