Best one yet. I actually laughed out loud. :)

I like it. I guess e^x like to play tag with himself.

My favorite nerdy math joke:

So e^x and c are walking down the street, and they run into the derivative operator. e^x acts all big and bold - "I'm not scared of you since you can't hurt me" - but c hides behind e^x because he knows that if the derivative operator takes him on then he's toast, but if he sticks by e^x's side then he'll be fine. Unfortunately, e^x's brazenness doesn't work out so well for him, since as the derivative operator comes closer he realizes he's made a terrible mistake. The derivative operator then introduces himself: "I'm d...dy..."

Yeah...

Just then, e^x turns to c and says, "Never fear, little c. y, my x knows how to reciprocate and look, we are approaching the origin with the evaluator here to judge that operator." Sure enough, d/dy is sentenced to work on a chain gang as they descend, with singular alacrity, into an infinite abyss.

Just gotta run backwards...

never gonna get me.. but I'll get close enough.. (is what I tell all my elusive e^x love interests)

but he's always on him, so e^x can never get away!! hah!!

SOMEBODY EXPLAIN THE JOKE...
I know, I'm no nerd, I don't get a lot of jokes

c e^x. Say it out loud.

this got me through a maths exam...
just saying

but d/dy would.

i lol'd