From the SmartSet:

"As the novelty of walking vanished, and as I entered a three-week period of solitude, my brain turned inward and began digging around among old piles of National Geographic and dusty stacks of vinyl records, looking for entertainment. This was my introduction to what Buddhists call Monkey Brain, the ceaseless chattering of the mind. During those three weeks, my monkey brain never shut up. It was like being locked in a small room with a hyperactive Irishman, like mainlining an AM radio talk show host, like being forced to watch the E! channel for 24 hours a day. I hadn’t known my monkey brain existed. Then it was all I knew."