“I think it’s amazing that all of those things have become part of our culture. He did not set out to write the great American novel, or to do a comic strip that will last 100 years … I think when people asked him, 'did you ever think your characters would become part of the culture' it puzzled him a bit and he didn’t have a very good answer for it … I think his answer was something like, ‘I just tried to put everything I had into the comic strip and do the best I could every day.’”
-- Jean Schulz, widow of Peanuts creator Charles M. Schulz, on the "classic" status of the comic strips. In an online chat, she also confirmed that her husband could be as "bitter" as you've heard. “Yes, he could be cranky particularly if he had person after person after person interrupting him from things … But he was overall a pleasant person."