I know this is the classic, but I just came up with a more elegant variation, without another world.
Toxoplasma infection makes you more likely to pet a cat. You like petting cats, but you are very afraid of getting toxoplasmosis. You don't know if you are infected, but you know this particular cat is healthy, so you can't become infected by petting it. Should you pet this cat?
I know this is the classic, but I just came up with a more elegant variation, without another world.
Toxoplasma infection makes you more likely to pet a cat. You like petting cats, but you are very afraid of getting toxoplasmosis. You don't know if you are infected, but you know this particular cat is healthy, so you can't become infected by petting it. Should you pet this cat?