Re: To help or not to help
It comes down to the fact that we are not here to save the world. Unless you have a big "S" painted on your chest, you are not Superman. Unless you have a badge and a gun, you are not a cop. You don't have to save the world, it's simply not your job.
Half the time, the person whom you'd be "saving" from trouble played a role in getting themselves in trouble in the first place. The girl you think you are saving from being raped may indeed be a prostitute arguing with her John over money. You never know. People often will try to drag others into their own drama in order to give themselves leverage in the conflict. And they'll use you as a pawn in the process.
Realistically, you'll never be in the right place at the right time. At best, you'll strive to be the hero and try to find ANY situation in which you can jump in and save the day. But you must ask yourself, "Am I really concerned about the welfare of the world, or am I just trying to fulfill an internal need to be 'the hero'?" The way you answer this question determines what course of action you should take.