I sometimes sleepwalk when I drink too much.
One time when I was about sixteen I got drunk on Jack Daniels and Guava/Pineapple juice (shout out USVI). I said goodnight too my friends and went to bed. The next morning I woke up wearing different clothes, muddy, and with a scraped arm. Apparently I got up after I went to sleep, drove to my cousin's house, had a beer and chatted with some neighborhood gangsters, was about to make a deal with one to buy a pair of suppressed 9mm pistols (which had my cousin and friends freaking out), slipped on mud (flip flops), fell pretty hard, drove myself back home, said goodnight to my grandmother, and went back to bed. I have no memory of any of it and I am assuming that my first, last, and only stop was to my cousin's house.
It wasn't my only incident but it is the only one where I can account for a portion of my actions and whereabouts. Also, as funny as it sounds, it is very scary.