When I was younger and in my early advanced study I was often getting into trouble for Doodling. I wish I had this article then. The Power of the Doodle: Improve Your Focus and Memory. Research Shows That Doodling Helps People Stay Focused, Grasp New Concepts and Retain Information

http://www.wsj.com/articles/the-power-of-the-doodle-improve-your-focus-and-memory-1406675744