Well, this is probably going to be different from the rest of you guys, but still:
One day, at work, a co-worker of mine turned to me and, somewhat jokingly, commented on how bad a job I did on stacking some things. As she did that, I remembered a dream I had about a little under a month beforehand, in which, for a very short part of it, a scene that was almost exactly the same took place. I even remembered saying to her than she had been in a dream I had shortly afterwards. You know, a feeling of De Ja Vu so strong that it implies, to you at least, some kind of precognative aspect. However, shortly afterwards, I couldn't remember the dream for the life of me. I remembered the scene in question, but no matter how hard I thought about it, I couldn't associate it with a dream I'd had. It was simply something someone had said to me a few moments before. I wasn't sure what I if what I remembered was real, or if I was having a memory laps, or if I was psychic, or is I was just insane. And I must say, not being able to trust your own brain is a scary ****ing thing.