I've just done my civic duty, and it feels good.
At London Bridge station, there was a woman "in distress", sitting on the stairs. I walked past, just like a couple of other people. I couldn't let it go. I went back, and asked if she was okay. She was totally lost, and had no idea how to get home. I don't know either, but London Bridge is a big train hub, so her best bet is the main station (definitely not the tube). I send her on her way (denying her request to take her there). Maybe next time I'll be better.
That woman may just feel a bit better because of me. I hope someone does the same for me one day (actually, they already have, albeit in different circumstances). Everyone should do this - it's easy, and it's remarkably rewarding.