While writing, painting or any other activity that takes a high level of concentration and focus I reach a point after a a bunch of hour of hard work. I run into wall and get frustrated or even irrationally angry. "RAWWWWR! Stupid writing! I'm going to become a plumber! Pipes can't be this frustrating! Rawr! And I would share occupation with super Mario! Damn this writing business! " Just a general silly frustration. I'm not displeased with the work and 5 minutes before I could been laughing with joy working. But then all of the sudden my brain goes on strike, overworked and tired and I need a real brake, like a hour walk with the dog before I can return to the work again. Does anyone else share a similar experience?