I do that all the time. As a matter of fact, that is one of my main issues that I want to work on with my T. I know that in my case it stems from childhood: not having emotional stability, as well as being abandoned and emotionally/physically abused, criticized etc etc, has led to me being extremely sensitive to others' actions, words, and observant of the slightest change in things, which makes me be constantly on guard, waiting to get hurt. So every time my T seems just a bit more distant or cold, I immediately erase from memory all his actions/words that prove he genuinely cares, and the only truth I can experience is his coldness and distance. It is painful indeed. It's like a well that cannot be filled.