They always expect something in return for their “act of kindness”, and a lot of the times, The request is something bigger, more expensive or harder than their initial favor. And the minute you show a slight glimmer of hesitation, they hit you with “unakumbuka that time nimekusaidia na…”
There is a saying in prison that you never accept when someone gives you a pack of gum, because you are now in depth to that person and they will use it to justify all manner of wickedness they will put you through. Normal society is full of these people as well, except they’re a bit more subtle about it, however, you are still getting f*cked either way.