Comment by pardon_me

We are human. Unfortunately all of our experiences with others change our perception of them, no matter how much awareness of their motivations and our history with them. We can try to ignore it and have patience. Apologies can help but relationships will constantly change.

It's certainly a failure point within us and something to be aware of to make effort towards understanding our own impact as you suggest. Sadly a problem with no full solution over long enough time periods.