Same thing happened to me when I had mine a few years back. I don't even remember going under, and next thing I know they're finishing up.
Same thing when I had a Tumor removed inside my skull. The Anesthesiologist said "Start counting down from 100".
"100,99,98..." next thing i remember is being rolled back into pre-op dizzy as all Hell. Anesthesia is like the chemical version of an alien abduction.