Chlorine. It’s in your pool, killing other peoples’ damn germs so they don’t infect you with God knows what. Probably like, pool herpes and swimming cholera and shit. You can’t be too careful with other peoples’ germs.
Of course, YOU don’t have any germs. You’re fresh and sanitary! You’ve already showered twelve times today, and it’s not even noon. You’ve sanitized every surface you touch before touching it, in case someone broke into your house in the night and licked everything with their disease-tongue. And for good measure, you’ve alphabetized all your soaps, cleansers, shampoos, mouthwashes, toothpastes, hand sanitizers and detergents. Just in case–you might need one in a hurry! There may be a cleanliness emergency! You can’t be too careful!
Not like other people. They are all filthy disease-factories, and they would kill you with one of their swimming pool infections if they could. It’s probably best if you never leave your 100% sanitary apartment. Seal the doors and windows with plastic. Boil all the air before breathing it. Cleanse your drinking water with Windex. Whatever it takes to never, ever get pool herpes.