If and when someone says you're not cut out for something, or you're not good enough for something or someone~Prove them WRONG! Don't get mad, infact smile! It confuses you're enemies. Yes, they're enemies, because if someone's not for you; they're against you. If they don't know about it, now friends; they're not against you. Or if they support you, but maybe don't agree with you or they're not on the fighting lines with you; they're not necessarily your enemy (smile here) I just don't want folks running around thinking everyone's their enemy! Hahaha!
Anywho, you should know what I mean! The point is. Don't allow people to steal, kill or destroy your dreams and positive thoughts! You own them! No one can deny the power thereof. Be a fighter for what you want or believe in. Because if you don't believe in yourself; who the hell will?!?!?
Like Nike said, Just Do It!