Prepare for the worst and hope for the best.
Lesson one: don’t take anything personally unless it is specifically directed at you. That will save you from a lot of unpleasantness.
Lesson two: do not smoke. Science has proven that smoking will shorten your life and likely lead to a painful death.
Lesson three: drink moderately or better yet not at all. This will save you from doing and saying things you may later regret even if you are too drunk to remember them.
Lesson four: save a portion of everything you earn. Pay yourself first. You can live on a lot less than you think. Ask your parents about things that they did not have when they were your age. They survived without those things and had enough left over to raise you. So can you. Make it easy on yourself by having your bank take money out of your paycheck and put it into a savings account. Save even if you do not have a goal. There will come times when you might need to tap into your savings in an emergency.
Lesson five: pay cash for everything. Try not to borrow money, even from friends or family, for anything except possibly a house, and then only after a substantial down payment. Credit cards are useful and offer more security than debit cards or wads of money. Just make sure you pay off the balance every month. If you use a credit card and pay the balance every month you will have the best credit rating. That way, if ever you absolutely have to borrow money you will be able to.
Lesson six: the journey is more important than the destination. Enjoy life as it comes. Being happy is better than being wealthy.
Love is good for your health. Hate makes you sick.