[npalmer76]

So, wearing a mask in public is not about avoiding getting sick. It is about not getting OTHERS sick. You may be an asymptomatic carrier and the mask filters your droplets out and keeps them from contaminating surfaces other people will touch. In many asian cultures this is considered common courtesy.

[pmachinery]

Some people may be courteous enough to wear a mask when sick, but most people wearing a mask in Asian countries are not sick and being courteous, they are (sensibly) trying to avoid becoming sick.