Into the twilight

I've had quite a few procedures now involving twilight anaesthesia - the one where they don't have to put you deeply under.

Yesterday, I had it again, and while waiting I said to the anaesthetist that I like the seemingly instantaneous way it works - a bit of different feeling going up the hand after its injected, and you think "I'm not sleepy yet.. will I feel sleepy in a second?", and next thing you wake up outside in the recovery area as if only almost no time has passed.  I'm not sure that it looks like that to an outsider, because part of the way it works (so I believe) is to induce amnesia of things done to while under it.  So maybe I do blink a little before falling asleep?  Do they talk to me when they are repositioning me on the way out to recovery and do I respond?  I don't know.  

Anyway, the anaesthetist said "yeah, it is very strange, isn't it";  which was a nice response indicating she still has a bit of a sense of wonder about how it all works.

I see from Wikipedia that there are 4 different levels of  twilight anaesthesia, and I don't know what type I have had at different times.    It does take a little while to fully come out of its effects, but I had a good sleep in the afternoon and then again overnight, when lately I have been having some sleep disruption.  

Have they tried treating insomniacs with it, I wonder?   Does it help reset the sleep clock?  

Just wondering...