"Very hard to explain the speed with which you drop from awake to sort of sleeping to "there is no me". The way back is a bit slower but harder to pinpoint, but I knew something was different in the recovery room."
There was no perception of speed in my case.
I just have a distinct memory of a mask being put over my mouth and nose and the nurse/doctor telling me to count upwards... and then I was in the recovery room.
No gap, no memory of going under or anything that happened in between. It's like the intervening time didn't happen.
Much like waking up from a dreamless sleep.