It's a horrible feeling when you don't understand why you did something.
That is an interesting observation. For my part I do not experience horror in those circumstances, merely curiosity and uncertainty.
I think it may depend a lot on how well the action fits into your schema for reasonable behavior.
I have mild OCD. Its manifestations are usually unnoticeable to other people, and generally don't interfere with the ordinary function of my life, but occasionally lead to my engaging in behaviors that no ordinary person would consider worthwhile. The single most extreme manifestation, which still stands out in my memory, was a time when I was playing a video game, and saved my game file, then, doubting my own memory that I had saved it, did it again... and aga...
Another month has passed and here is a new rationality quotes thread. The usual rules are: