Sometimes you realize that you cannot. No matter how good you are, there are still things you can’t do. Put it simply, I cannot run as fast as a tiger for sure.
The problem, or maybe the faith, is that as a teenager, you believe you can do something great. You put a lot of effort into it, and finally it sucks. Time after time, you lose the faith in yourself.
What’s wrong with that?
You are not THE ONE for that job. There are guys out there much better than you. What you have is the unique idea. From ideas to practice, wa liao, such a long distance.

Is it true that you can do everything if you have enough faith?

As I pointed above, no. But I believe, yes. It’s just whether you can find someone, or something to help you accomplish your dream.