Often when people are semi-awake, they find it easy to resume the dream they left off. I've been experiencing an 'extended' version of this. Sometimes as I fall asleep, I remember dreams from the previous morning. A few times, I found myself continuing the dream from the night before, probably because I recalled the dream in the hypnogogic state, and it was the last thing I was thinking about as I fell asleep. It's kinda cool.