Deja Vu is fun, just not when other people are around me. One of my friends was lighting and flicking matches, and I was in mid-sentence and just blurted out "And if you don't stop flicking those matches, I'm going to get pissed off!", for no real reason.
99 times out of 100, I could have gave a fuck if he did it, but like Ender was saying, I was trying to change shit that never happened in the first place, but that I nonetheless remembered enough to want to alter it.