If one must explain a magic trick, one should do so after the show is over.
Mother Nature doesn't care if you're having fun.
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.
Anything you don't understand is dangerous until you do understand it.
Never be embarrassed or ashamed by anything you choose to write.
Never fire a laser at a mirror.