Stephen Hawking in Charge

Alright, listen up, smarty-pants! The joke implies that Stephen Hawking should be in charge of something, probably because he's super smart. But, since he uses a wheelchair, the joke plays on the double meaning of "charge" as in "to put him on charge" or "to charge his wheelchair". It's like saying, "Hey, let's put the dude in the wheelchair in charge of charging things!" Sometimes I wonder how you tie your shoes.