But he retains fond memories of his time with the prog metal outfit � and he's grateful they tolerated his obsessive-compulsive disorder. Portnoy tells Modern Drummer: "With Dream Theater I very much ran the show because my OCD allowed me to handle the additional roles.

"Luckily those guys always trusted my direction. OCD can be a detriment, though; I know it sometimes makes my wife crazy, and I'm sure it must have driver the guys in Dream Theater crazy at times too. But they rolled with it.

"When I first met John Petrucci and John Myung when we were 18 years old, I think they immediately recognised that part of my personality, and they were comfortable with that dynamic. John Petrucci and I balanced each other out through the years. He never cared much for all the little details and organisational stuff, and I never cared about the business or financial aspects, which he was very good at."