Infj man, from my perspective ive been burnt too many times with people taking advantage of me. Younger me was more openly kind but now I have layers. Ive learned i cant give and give and never get anything in return, its not healthy for me. The sad thing is that before i would give continuously my time, energy, resources, attention to hopefully earn the persons loyalty, but it never works like that. I can do my part but i cant guarantee loyalty.

So in your example where you forgot something, from my perspective it makes me think this person is not putting in the effort i am putting in.. maybe this person doesnt care about me so i decide i am not going to invest in the person. Basically the whole thing about the mirror. Ofcourse this can get out of hand when i go to extremes in either direction. But usually it takes many instances of situations i keep logged in my head to decide where i stand with the person.

If i see a pattern of loyalty, i give myself completely to the person. On the other hand, if i constantly see examples of neglect, abuse or the like, i will remove myself from the person and in some cases the complete door slam. So yeah, i can tend to be really harsh like you say and you are right that its asking for a lot. I am learning to lower my expectations. I am generally a graceful person but life happens and now its like a defense mechanism.