It's like your children talking about holidays, you find they have a quite different memory of it from you. Perhaps everything is not how it is, but how it's remembered.
And when you're on your own there is that terrifying possibility that you may be the only person on the planet who thinks it's funny - and you have no way of finding out.
The comedians all finished their acts with a song. They would get a certain amount of money from the song publishers and would use that money to pay the writers. None of them paid very much for their comedy material, but it all added up.
And if you can offer an explanation as to why it doesn't work then you've got to the whole root of comedy.
Then after that came word processors and it's hard to make those laugh.