It doesn't happen often (usually 4-5 times a year and when I'm by myself with silence) but I feel as if everything in my life becomes very intense, every movement and sound feels as if it's too full on and everything is forced.. It's like a huge negative cloud has appeared over me and my motivation levels can go from 100 - 0 in seconds and that there's no point to anything. It usually doesn't last long (15-45 minutes) and after it I feel fine.