Interesting question! I've had 2 surgeries in the past couple of years. Thyroid surgery was the longest at a few hours. I woke up and asked for a drink of water. I couldn't remember anything that had happened after getting to the hospital, even though I had a two hour waiting time before surgery. (I couldn't remember any of it.)
Then I had gallbladder surgery a few months ago. It was a shorter procedure. I could remember being wheeled in to the operating room and a mask being placed on my face. When I woke up, I didn't recall anything at all. My mind was completely blank.
I also had anesthesia for a outpatient procedure and it was only a 20 minute ordeal. When I woke up I couldn't remember anything after the nurse taking my vital signs before the procedure.
The only thing I can recall from anesthesia is waking up and not remembering a thing! LOL