Not much knowledge of the laws of physics, though.

We're walking the dog. I have the leash:

The historian: (facing me and Bruiser, runs a few steps backward) Just like Jimmy Piersall.

Me: (hoping for no backward running mishap, especially since it's dark out--) ...now why were we remembering Jimmy Piersall, again?

Historian: It's the 50th anniversary of the Mets. Remember? he celebrated by running the bases backward.  (pauses, remembering:) Of course, Boyd, who we used to play doubles with, used to run the track in the field house backward, so he'd be in practice for running to get a ball. He tripped and broke his ankle.

Me: [remembering another one of the historian's acquaintances who did something else nutty like this...who was it?]

Historian: ...and also Craig T., who broke something or other when he was demonstrating to his wife how he could change directions in mid-air.

Me: (chuckling on the inside)

Historian: ...had a Ph. D. in philosophy.

COUPLET.