My old 4th grade friend made up this little ditty way back in '78:

"Teachers are dumb, teachers are dumb,
They don't even know what's one plus one."

And who could ever forget this one:

"School's out, school's out
Teacher let the monkeys out!
One went east, one went west
One went up the teacher's dress!"

But after high school graduation, we sang a slightly different version:

"School's out, school's out
Teacher let the monkeys out!
One was jailed, one prevailed!
Both asked God 'how have I failed?'"