I've got five or six unpublished stories kicking around looking for somebody to buy them.
The dinosaurs became extinct because they didn't have a space program.
How much intelligence does it take to sneak up on a leaf?
In challenging a kzin, a simple scream of rage is sufficient. You scream and you leap.
As for AIDS, it's a plague. We are human, we get plagues. They come along every so often, kill off two thirds of the population; in the next generation it's a quarter; after that it's a childhood disease.
The Unexpected always comes at the most awkward times.