Written stories must be changed to be recited aloud. When you find a story that you like in a reference book, you cannot say it exactly as it is written or you will sound stupid. You must knock out the he saids and she saids. Don't give a history lesson when telling a humorous story. Put yourself into the story to make it believable.
Fake truth is essential to humor even if story is totally false.
The exception to the need for fake truth is when you are telling an exaggeration. Then anything goes. I came home with 14 harpoon wounds.