The author has never worn a mask or they wouldn't be spouting such nonsense. Professionally fitted? They usually come in small, medium and large. Pick the right one. They need to make a good seal on your face, so lose the beard if you really need a good seal.Other than that, keep them snug enough so that when you inhale, the air enters through the filter cartridges and not through leaks around the mask. Because the filters slightly restrict airflow the mask tends to pull in tighter as you inhale. Uncomfortable? I guess comfort is a personal thing, but I've worn a half mask with N95 cartridges all damn day without too much discomfort. It sure beats hacking up drywall dust for the next 3 days.