Also, learn about what economists call "sunk costs." If I give someone $100 on Monday, and he spends $50 on candy, he’ll probably regret that purchase on Tuesday. In a way, he’ll still think of himself as a guy with $100 — half of which is wasted.
What he really is is a guy with $50, just as he would be if I’d handed him a fifty-dollar bill. A sunk cost from yesterday should not be part of today’s equation. What he should be thinking is this: "What should I do with my $50?"
What you are isn’t a person who has wasted 27 years. You are a person who has X number of years ahead of you. What are you going to do with them?
quora is quite awesome sometimes.