What kind of person was your hero before he got superpowers?
What sort of job/educational background does he have? What is it about his background that will appeal to them?
What sort of problems did his world have before he became a superhero? (Or did he have a happy and carefree childhood until he saw his parents get murdered?
Many heroes have scientific or technological skills, etc.
(Which personal feelings/experiences influenced that choice?
If a friend noticed anyway, how might he try to explain them away?