When I in high school, I had a deep-seated intrinsic belief in myself that I believe most kids that age do. When you're 16, you have this feeling that world is your oyster, all problems are surmountable, and a general optimism not only in yourself but in the system at large.
As you get older, people begin to chip away at that belief. They tell you to be scared of risk, what the "safe" path is, and that you should be realistic.
When life is a race with no real ending, this means having that you have to fight to retain that conviction every day - turning the fear of the unknown into courage. Only then, can you be free.