“I think we just vastly underestimated both how hard it is to purposely engage in pleasant thought and how strongly we desire external stimulation from the world around us, even when that stimulation is actively unpleasant.”

Read more:

http://www.news.com.au/lifestyle/health/many-people-prefer-pain-to-time-spent-alone-thinking-study-shows/story-fneuz9ev-1226977219972