You are 21 :-)... You will probably change of idea's more often and that's fine. We live in such a fast world today that it's almost impossible to stick to the same thing for the rest of your life. You never know enough. The more you know, the less you feel like you know because you feel like there is so much more.

in poker we always say "It takes a minute to learn and a lifetime to master"... That's the same for growing up really.

I don't feel different today than I did when I was 18 but I'm sure I changed a lot. Experience is what matters. Falling down and failing is the best experience at all. 

Keep me updated :)