You're right, i do close it to flush a poop. I don't to flush a pee.

Lots of people say this, but i sit and stand on it anyway.

When i was very young, i was practicing my saxophone embouchure on my mouthpiece while i was going to the bathroom. When i flushed, i looked down at the water going down the toilet bowl, and my mouthpiece fell into the toilet and got flushed away.

I can't go back in time, so ever since that day I've taken pains to remove the risk of things falling into the toilet, especially while it's flushing.

One example is if i have to retrieve something from the cabinet on the wall above the toilet, i make sure the lid is closed first.

you realize you breathe in way more nasty nasty microparticles going outside for like 3 min that you do from your toilet flushing a couple of times a day? lots of fungus, bacteria, viruses, spores, etc.

your immune system exists dude. and it needs light exercise.

the only way aerosolized waste is making you sick is if you like go inside a sewer or waste disposal tank where it's intensely concentrated, and it's really the methane that's doing you in, as the bacteria don't float.

also your basic breathing through your nose and mouth is shooting out way more nasty shit that actually can infect other people. by paranoid logic we should all be using closed breathing systems at all times.

My guest room has a rarely used toilet with a plastic, slow-close lid that is opened, at most, possibly twice a week. We recently had to replace it because it was very visibly moldy to a disgusting degree.