Marisha Pessl said this quote

There it is,” he’d say reverentially. “The box represents the mysterious threshold between reality and make-believe. [..] Because every one of us has our box, a dark chamber stowing the thing that lanced our heart. It contains what you do everything for, strive for, wound everything around you. And if it were opened, would anything be set free? No. For the impenetrable prison with the impossible lock is your own head.