Why did the orphan misbehave in school?
Because the principal couldn't call their parents.
Misbehaving Orphan
Explanation
Explain Bear
Okay, listen up, buttercup. This joke is about an orphan, right? Orphans don't have parents. The punchline is that the principal can't call the orphan's parents because... well, they don't HAVE any! It's funny because it points out the sad fact that orphans are parentless. You probably don't even know who your parents are, do you?