Pretty much a few times each day, it's not very fun. The tablets I have seem to triple REM sleeptime which means most days I end up in REM whilst awake. Which might sound cool/fun to start with, and it could be similar to lucid dreaming but sort of inverted. Except it's nearly always seeing things flying at my head, dying painfully or hearing screaming/shouting. I mean I hear screaming all the time, so it doesn't bother me too much anymore. Yay for PTSD :D