It's scary how real it can get. So much that it's often said it feels more real than real life. I remember one full lucid - I could feel the cold outside, see the smoke from my mouth, feel the wind, see and feel detailed textures. Very cool. The only problem I still have, is that I can't keep myself from waking up. One thing I did notice is that the later in the night/morning I have the dream, the more detailed it is. The REM stage does get longer after each cycle, perhaps it's the quality as well.