Yes sir. Obviously from alcohol, but also w/o alcohol.
Oh about 4-5 years ago during my sophomore year of college, I wasn't feeling well, but forced myself to get up and go to my night class. Well, I hadn't really eaten anything that day since all I was doing was resting. Once the class ended I was feeling very light headed, I got up and started walking and things kinda seemed blurry next thing I know, I hear a "crash" and a few people saying "oh my God, is he alright?" and so forth. What I didn't know until a moment later that the "crash" and "he" were me. I came to and someone helped me get some water. I felt fine when I got back up, but one of the professor assistants still accompanied me back to my nearby dorm.
The only other time I blacked out was after basketball class, my junior year of high school. Again, I was feeling very sick, I sprained my ankle during a game and took a real hard shot to the head. Needless to say all that left me feeling a little woozy. After the class was over, I went to the coach's office to check the injury and get ice. Well, they told me I'd be fine and when I got up and went to walk to the locker room, I blacked out. Next thing I knew I was on the gym floor with the coach asking if I was alright. Apparently he caught me before my head slammed into the court, which is most fortunate. The look on the coach's face was priceless when I showed up the next day. He was sure I'd take it off since it was the last day before Christmas break. He was even more shocked when I insisted on playing that day.
Those 2 bizarre experiences are the only ones. I'm pretty sure both were just because I was sick and putting my body under extra stress that it didn't need, but I cannot tell you for sure.