> Nothing in between, nothing like that thing you feel when before you fall asleep at night or wake up in the morning.

Same. I was put under twice and both times it was like someone flipping a switch from conscious to unconscious. When I woke up it was like nothing happened save for a slight groggy feeling. It was not like sleep where you feel rested, as if you lost time.

edit: to add when going under the first time I was laying down on the operating table as the anesthesiologist made small talk with a nurse I suddenly felt super high while the room started to spin - POOF out.