An elephant drinking from a stream spots a tortoise lounging on the shore.
He grabs it with his trunk and flings it into the jungle. A passing zebra asks, “Why did you do that?” … …
“Forty years ago that very tortoise nipped my tail just for fun, “the elephant said.
“Wow, forty years ago! How did you remember that?”
“Well I have turtle recall, “replied the elephant.
This joke is included in the Black Book of Jokes. You can order it from here.