I've had realistic dreams too that then I can't figure out if they're real or dreams... but nothing so funny as dreaming that someone was telling me to get out of bed! But back when I was really depressed (I was being treated), I used to dream a dream, then wake up, start going about my day - then the alarm would go off and I'd really wake up, having heretofore only dreamt that I'd awakened. My therapist said it was a classic example of dissociation, which is this great defense mechanism so that the bad things that are really happening aren't really happening to you. So I started checking in my dreams (oops, typoed creams, ha ha), and once actually had something so strange going on that I decided I must be dreaming, so I pinched myself, and when I didn't feel the pinch I knew I was really dreaming... just like in the books! It was really funny at the time. I laughed so hard I woke myself up...