Don't be a nice guy. Be someone with attitude+opinion and brave to express it.
No, you don't have to be hard on yourself. That brilliant part of you comes out naturally as you embrace your goal, as you really really want+aspire to achieve something.
So, find that most important something and stick to it first. The rest will be taken care all by itself.
(And, these are my last words before I immerse in that something.)