this happened to me once a year or so ago, and I thought it was a one-time occurrence, but it happened again this week:We had to perform compositions in a class, and it was my turn. From the moment I stood up, until almost the end of class, I can't remember anything. I don't remember playing the piece, I don't remember handing my manuscript to the prof, I don't remember if anybody said anything to me, or if I said anything back. it's really creeping me out, and it can't be good. I am sure it has to do with some combination of stress and concentration, but I need to know how to control it somehow. Everybody said I did just fine and acted normal, but it's just too weird.