That's mostly because they rely on the fact that once you help someone they feel indebted to you that all breaks down if the person your helping feels no obliga

That's mostly because they rely on the fact that once you help someone they feel indebted to you that all breaks down if the person your helping feels no obligation to return the favor. A lot of people use this behavior to manipulate other people so it's a good idea deprogram it in yourself. Whenever I help someone i don't expect anything back in return that's probably why I'm ok helping anyone regardless if i ever meet them again and i expect the same no string attached help. Don't get me wrong though i never 'expect' anything from strangers however if they offer to help (which is a nice surprise) that the type of help i expect. You want to help me? Fine.