I think I've experienced that as well, though not as you have explained. It's probably due to grogginess in my case. I wake up, but don't know I'm awake, so I assume being awake is the dream...and that what precedied it was real life. You remembered your dream very well. Have you ever dream an interesting dream, awoke to replay it in your mind, and then fallen back to sleep only to forget most all of it the next morning? To me, they seem to fade the more sleep that follows them.