I have a tendency to forget, full stop. I sometimes try to stay mad at someone that's wronged me in some way, but then about an hour later, halfway through a conversation with them, I'll remember I was mad, but at that point I've already been friendly with them so I can't go back to being mad.
Overall, not a terrible trait to have I suppose, but I think it makes it easier for people to take advantage of me sometimes.
Try being on the apps for a year without a match. Really helps boost the old self esteem.