As others are telling you, anesthesia is very hard on the body, on some more than others. If you've never had surgery before, you won't really know until you're there. My VSG was the first surgery I ever had . I did wake up right after surgery, in the recovery room, but I felt soo groggy and "out of it" that my only solace was just sleep through it.
I slept for most of that first day (surgery day). It didnt bother me much, I wasnt nauseous or anything else, just felt sooo tired and sleepy. My family was there chatting all around me, I had some visitors and was never aware that they were there. Like I said, lol, "out of it".
Good luck with your surgery. All in all, this experience was a cakewalk for me and I would do it all over again if I had to!