This is a very good question and I am sure many of us will feel a little shame because is very easy to forget when people helps us, maybe because as you said, we believe that we have right to receive support, forgetting that we should be reciprocity and do our part.
Thanks for being always genuine and reflexive in your thoughts.
If you forget someone there is no shame.
If you feel shame you didn't forget.
If you are greedy and abuse for gain (hackers, scammers, greedy people, corrupt people) there's also no shame.
True shame will change you and you will suffer from the deed and try to change
Beautiful words, and makes sense at all!