There are periods of REM sleep, rapid eye movement (dreaming) these happen every 90 minutes after you enter the first fase were hormons work and is described like mind resting, this is the fase that is important for children to grow. The times between REM periods get shorter through the night till a point were you just have REM periods after like 6 or 7 hours if I recall well.

So no, you don't lay down and dream. But that would be awesome.