I get lucid dreams all the time. It usually happens in combination with a thing called sleep paralysis too. I've been getting that since I was about 12 years old & didn't even realize there was a name for it until I read about it on the net a few years ago.
Your brain wakes up and you know you're still asleep, but you can't move.
Plus, you have this weird feeling that there's a presence in the room with you...like somebody walking around your bed.