Just for fun, I put on face mask that’s occasionally used in my lab. It’s 3M-N95 Particulate/Flu Mask.
Face mask helps protect us from small particle in the air (not 100%). Most Flu virus transmitted to small liquid droplet in the air, door knob, hand etc. So Face Mask is just the first line of protection. It’s not a fool proof from Flu Virus. So wash your hand regularly, and don’t put your hand into your mouth.