[@Afro Samurai]
Pain is exciting. By definition. No matter what your state of mind getting hurt will trigger 'excitement', which can then lead to emotions such as fear, anger, or in some cases arousal. But pain cannot be 'boring' to a normal human mind. If someone were to encounter pain as boring that would require a seriously messed-up brain chemistry, as the excited reaction to pain is as fundamental to the human mind as something like our survival instinct, or human empathy.

So effectively, he's going to be turned normal again by exposure to pain. Even if fights bore him, somehow, pain will always revert him back to normal. While usually when you're in a situation that causes pain that's exactly when you don't want to become normal. 

While I am highly amused at the idea of a Doomsday-looking monster watching Spongebob while supers are fighting in the background, it seems to me like this character won't be able to do much. Unless his trigger actually fundamentally changes he won't be able to participate in any real combat, and if he actually pisses anybody off they can kill him with a handgun and a book of insults.