Don't let anyone tell you that you don't have what it takes.
To the people that do:
saying someone can't, rejecting someone's goal, even if they are pursuing it in the wrong way in hopes to finding a right way, is the wrong way to treat someone's goal. Instead of saying you can't, or "you don't have what it takes"...ask more questions, ask the person pursuing why they want to do something, ask how they plan to get where they want to go, help them see a straighter line, the righter way, don't dismiss someone's pursuit directly. It is a shame on you.