I have seen people in my neighbourhood (Bermondsey in London, UK) struggling with luggage twice, luggage that was clearly far too much for them to carry on their own. Both times I offered to help them take it from the train station to wherever they were going. The first time the man accepted my help, the second time the woman politely declined.

Even the first time I detected an uneasiness, partly because we were strangers of course, but also I got the sense that the man was very wary of putting on me at all. Perhaps because people like not having obligations towards their neighbours it feels wrong to accept help and thus set up an expectation of reciprocisity. Maybe this then leads to not offering help because it is assumed it will be refused?

London is a particularly atomised place of course, back home I think I would have got a very different response.