As far as memory loss/time travel goes, I rarely (if ever) woke up and was like, "holy shit, what happened last night?" However, I've had instances where I'd wake up as normal and some point in the course of the day would reveal that there were details of the previous night that weren't present in my mind.
Example: I used to have this adorable habit of chewing on people's scalps when I was blitzed, sometimes making verbal indications that I wanted to eat their brains. It was usually a sign of solidarity and affection. (
http://home.uchicago.edu/~stp/sethhillary.jpg is the one documented example I know of on the web.) Anyways, back in the fall of 2004 I got drunk one night and the next morning I remembered being pretty out of it the previous night, but I thought I had a good hold on what all happened. I was playing around on Facebook, looking at the group for my house. My dorm house had about 90 people in it, but Facebook was still pretty new so the group didn't have many members. At one point I looked a profile of this beautiful Cuban girl whom I'd never met, so I asked my roomie if he had any idea who she was and why I'd never seen her around the floor. His response was one in perfect deadpan consternation, "Seth. Last night, you tried to eat her brains. As I remember, she wasn't really happy about it."