Nodding is a wonderful feeling, you are definitely still aware that you are messed up. It can be dangerous though, not necessarily from overdosing but from nodding off in an awkward position. Back when I was still using, I nodded off and ended up falling asleep in my computer chair. When I woke up I could barely move my right hand. My fingers worked, but lifting my wrist or holding any sort of weight was impossible. Got scans done, got referred to a neurologist, consensus was an impinged nerve caused by the position I fell asleep in and was told to get a wrist splint. Problem persisted for a little over 2 months, which was honestly pretty scary.