The author of the Peanuts comic strip was a sad and passive-aggressive dude, says biographer David Michaelis in the recently published Schulz and Peanuts: a Biography. Only 70 pages into the book, I can't put it down. My Mom turned me on to Peanuts books back in 1962 and I've loved the characters ever since. Especially Linus.
Schulz drew almost from birth. The guy worked and worked and worked at it -- in every spare moment. That is, after all, how one gets good at something -- and stays good at it. More on Schulz as the reading progresses.