Audience participation

Hello readers, I need your help. Perfect characters are boring. Like everyone else John Doe is flawed. I need your help to determine what that flaw is.

I am specifically looking for 2 types of flaws.

Personality flaws (ie a phobias, shortcomings, psychological disorders, megalomania, etc.).

Weaknesses. Is there a situation where his powers fail?

Post comments with your ideas. I will provably puck one of each. I look forward to your responses.