Okay, so you're a superhero, let's say. Your super abilities are not really important to this discussion, except that they must include an ability that comes into play in the scenario below. Also, because of the nature of your abilities, and the community you live in, it's somewhat important that your secret identity remain secret.
Let's say that you're on the bus back home, after a long day at work. By work I mean the "normal" job you get paid to do in the real world, where your superhero abilities don't *necessarily* come into play.
Okay, so you're on the bus back home. The bus is moving along at a good clip. All of a sudden it stops short, causing people on board to lurch forward. Most passengers are able to compensate to the shifting physics. The eager newspaper reporter, with the camera at the ready, has compensated. So, too did the girl or guy upon whom you have a secret superhero crush. But one passenger, a young child, a young boy, let's say, a happy young boy, he cannot compensate in time. He's sitting in such a seat on the bus that causes him to fly out of his seat, fly forward, towards a pole on the bus. A dangerous, hard metal pole. Now, because you have the ability to suss out the situation, you see that he's going to fly face first into the pole, and probably do some serious damage to himself. You also know that if you act quickly enough, you can use your abilities to catch him. You can stop him from smashing face first into the pole. Problem is, if you do, your quick action will more than likely cause people to wonder how you did this. Some of the more clever passengers will likely piece together that you've got superhero abilities. If they do, then it may very well become more difficult for you to perform your superhero obligations (whatever they are for you).
So, the question is: Do you save the child and risk revealing yourself? Or do you let the child suffer the accident and save your identity for more *important* moments?
Personally, I allow the child to smash his face into the pole.