When I was in high school I used to have a lucid dream at least once a week. I'd say they felt VERY realistic. I had emotions during the dream, mostly of excitement, because I knew I was dreaming and could do whatever I wanted. Certain experiences have stuck in my memory through these dreams. (i.e what flying feels like, having a tail, sexual relations with people.) I know none of this has happened so it can't be a real memory, but it feels VERY real. I've slept with friends in my dreams who behaved/smelled/looked much like they do in real life. It felt really awkward talking to them the next day..