"Comedy is simply a funny way of being serious." -Peter Ustinov
So Maeve has a totally passable Chicken Joke that she made up herself, completely unaided, and it both makes sense and is funny: Why do chickens sit on their eggs? Because they don't have chairs!!!
We like this joke. We made the mistake of laughing at it, which means it now gets told whenever Maeve would like to make me laugh, which is regularly. But she also thinks that she is now a Joke Genius, and likes to make up other jokes. Like: why does the bird sit on its egg? BECAUSE IT DOESN'T HAVE A UTERUS!!! And other such nonsensical gems.
Part of me wants to laugh at all her jokes, because it's easier than explaining why her joke isn't funny or doesn't make sense. Humor is a difficult concept to grasp, let alone explain, let alone explain to an almost-four-year-old who just wants to get a laugh. Instead, though, I say something like Hmmm, I'm not sure that joke works yet. Keep working on it. Which is as nice as I can be about it without giving her a false impression, I think.
I don't think she's destined for a career at Second City or anything, but she certainly has her moments. I showed Maeve her very first Monty Python sketch the other day, The Ministry of Silly Walks, and she was instantly in love with it and trying to make up her own silly walks. Then she put her underwear on her head, which shows a pretty good comedic instinct, I think.