Imagine you have a mask, you take it off for some reason (say to eat or drink) and put it in your pocket, it gathers tons of bacteria, you then put it back on y

Imagine you have a mask, you take it off for some reason (say to eat or drink) and put it in your pocket, it gathers tons of bacteria, you then put it back on your face. The warm and moist environment lets that bacteria spread, and you sit there breathing in through that colony of bacteria for the next two hours.