I'm trying hard not to be one of those people. Sometimes though, for whatever reason, a long time has passed since I've talked to someone. This is compounded by the fact that I know a lot of people who live in different countries. Fortunately, the people I have contacted when I need something, have in general been very supportive. I am making a conscious effort to be better about keeping in touch though and I certainly take time to help people that go out of their way to ask me for help.

I understand that your point of view comes from not wanting to be exploited or taken advantage of. Hell, I used to have a very similar point of view, but as time has gone on, my attitude and approach has changed. Now, if someone asks me for something and in the past, they've always asked for something but never returned a favor then I'm less helpful if or when they ask me for help. For example, I might simply point them in a direction and leave it to them to figure it out. As if learned though, sometimes one is in a bind and when someone can help but chooses not to out of some kind of feeling of revenge or comeuppance, well, both parties lose.