Something pretty weird happens every so often in my dreams. I'll be in my dream, thinking it's real life as usual (I still haven't had a lucid dream), and I'll have a sudden memory of a dream. My dream self might relate it to something else in the current dream, or it'll just pop into my head randomly. When I wake up from my dream, I'll think of the memory I had, and at first I usually take the memory as an actual dream I had at some point in the past. But then, as I start to really think about it, I realize I can't think of a time in the past in real life when I remembered this dream. So it makes me wonder if it really was a dream I had, or if it's just a dream I made up within dream... it's very bizarre, and my mind can never really decide.

I don't know if this happens to anyone else, but I'm curious about what your guys's ideas on this are.