Read this strip at gocomics.com.
Another of the "Charlie Brown: Budding Cartoonist" series. In these strips Schulz pokes fun at his own pretensions, but they also show how engaged he was with his craft.
One thing I really like about all these is that, for all of C.B.'s faults as a cartoonist, he at least knows enough to work large. Held edgeways, that sheet of paper is as tall as he is, sans head.