I had a lucid dream two nights ago wherein I acquired lucidity only after I fell asleep in the initial NLD. I woke into a dream within a dream, realized that I was dreaming, and went off to have a normal flying lucid dream. But the entire time I was lucid I thought that the reality of the initial dream was my waking life. It wasn't until I woke into physical reality that I realized something was off. It took 5-10 seconds for me to gather myself and lock into a single reality. I have this dual cognition experience every once in a while, and always in the morning just as I'm coming out of a dream. The dream within a dream is very rare for me though. I love having dual cognition experiences because it shows me how interesting our minds really are. I had one a couple months ago when I was on Norco after an operation. I could close my eyes and be in the dream, open them and be in my bedroom. Very cool, though it lasted only a short while.