I didn't get this one as a kid, reading Peanuts compilations from the library of our elementary school. I didn't get the meaning of the phrase "holding it over my head". Just another demonstration that Peanuts isn't really made for children.
Circuses really aren't all that hot when you think about it. Too much forced joviality, too much seediness just off the sidelines. (Of course, the seedy atmosphere is why some people like it.)
Too many clowns.