One nice thing about masks is that they remind you to do other good precautionary behavior. Like don't touch lots of items/surfaces. Don't touch your mouth/nose/eyes (I use a tissue if/when I need to). When everyone you see is wearing a mask, it reminds you not to let down your guard.
I've always been a little germophobic, so for years I do things like use the back of my hand on the overhead handrail on the subway, instead of using my palm and fingers. And I don't like shaking hands. At basketball I just tap a guy on the chest with the back of my hand. Avoiding high fives, partly for hygiene but also to protect my many damaged fingers. And I've always thought that sick people shouldn't come to work. Which is far too common. And I've always moved away from people who have a cough or sniffle or are sneezy, if possible.
It's odd, we know how viruses and other sicknesses are transmitted yet we engage in a lot of routine behavior that perpetuates transmission.