Because if his punch line doesn't work, you still get a kick out of it.
A doctor
They both stop working properly when you open windows.
When he was told to "go big or go home," he only had one option. (I've posted this joke here before, but I believe I've been the first, so if you recognize it as a repost it's because I wanted to tell it again!)
Don't worry, they'll tell you.
Kid: At the Joke shop.
An anti-joke.
He tripped a fan
Because she was a litter bug.
None, he just has some WATAH!
Gent Lee (Gently)
There's no punch line.