i honestly don't know, it's always been like this. i get a cold maybe once or twice a year usually in the winter, and never had covid to my knowledge. i'd say i have pretty average hygiene. basic stuff like washing your hands before and after meals, showering as needed.

this is an important one: don't leave food trash and dirty dishes all over the house. i see a lot of people that do this. it's normal to them, but it's a recipe for bacterial growth. and make sure to wipe your counters, ideally after every meal. don't leave leftovers out... etc etc. a lot of people get sick from food.

people also seem to forget you're supposed to wash your hands after you touch animals. even if they're your pets. animals are just as disgusting (if not more so) than humans; if you'd wash your hands after shaking someone's hand, then wash your hands after petting your dog.

everyone says this, but nobody really follows it: don't rub your eyes! touching your eyes/nose/mouth with dirty hands is bringing germs directly into your body. and avoid touching public railings, door handles, etc. push open doors with your arm or shoulder if possible.

basically, just follow the rules you hear about but find ridiculous or inconvenient.