"Life might be a bit troublesome if I stay this big," you think to yourself. As your body quickly decreases its girth, you think about what SORT of life your protecting.
No family, few friends, shitty job; a nobody.
"Not for long," you think to yourself with a smile.
A body can create a world of good--or evil--with power like yours. As you stand there, having chosen the build of the average jock or underwear model, you realize you're just like all the superheroes and supervillains you see on the news.
You could be anything, do anything, even be anyone.
Practically a shapeshifter with punch, you really could do anything.