If you want to give someone a task they'll think is impossible, tell them to write a timeless comedy.
Not only would that somehow require advanced knowledge of what people will like in the future, but it kind of works against usual limitations of jokes themselves. As Seth Rogen put it, "Jokes are not things that necessarily are built to last."
That's not only because tastes and sensibilities change, but jokes can also age poorly for the more boring reason that they reference something that was a big deal at the time, but that nobody cares about now.
But whether we can put it down to his imaginative streak or to wisely picking timeless targets, making the laughs echo through the ages is something that comedy legend Mel Brooks not only managed to pull off, but essentially made a career out of doing.