Bob Hope had a vault full of jokes that he could go to when he needed material. He might take a 40 year old joke and change a few bits to make it topical and reuse it.
Red Skelton wasn't so organized (or rich). He was apparently also paranoid about other people stealing his material. So he had a briefcase full of jokes handcuffed to his wrist when he traveled.
It's much easier to memorize something when you can go back to the written source and see if you got it right.
Bob Hope had a vault full of jokes that he could go to when he needed material. He might take a 40 year old joke and change a few bits to make it topical and reuse it.
Red Skelton wasn't so organized (or rich). He was apparently also paranoid about other people stealing his material. So he had a briefcase full of jokes handcuffed to his wrist when he traveled.
It's much easier to memorize something when you can go back to the written source and see if you got it right.