They have obviously never met my wife.
I can run jokes one after the other that get laughs from everyone and she just looks at me.
But let me reach for something on the kitchen counter and catch my head on the end of a cabinet door (OUCH!) and she is rolling on the floor.
Sounds like my wife. She can sit through hours of the funniest stand up comics without laughing.
The only Schadenfreude she enjoys is when some guy in a movie gets hit in the balls.
Dude, my wife must be a clone of yours, she couldn't buy a sense of humor if KMart had a sale when it comes to jokes, but if I do something stupid, like trip, bash my skull, or smash a finger, she will come close to wetting her pants laughing.
A good example is when she strung a 1/8 nylon rope across our back porch on New Years Eve so she could hang our sheets and blankets out to dry (it was a beautiful day here in SW Az) and left it up after she was done.
Well my dumba$$ was playing with the dog, he started chasing me, I ran off the porch, and BLAMO! I get clothes-lined! She falls to ground laughing uncontrolably. She still thinks it's the funniest thing she's ever seen.