If one only wished to be happy, this could be easily accomplished; but we wish to be happier than other people, and this is always difficult, for we believe others to be happier than they are.
The future isn't written in the stars. There are no guarantees. So claim your adulthood. Be intentional. Get to work. Pick your family. Do the math. Make your own certainty. Don't be defined by what you didn't know or didn't do. You are deciding your life right now.