In this case I think masks can work very well, but the surgeon is trained. All healthcare workers actually take mandatory classes on how to properly use and handle their masks. And then they have to practice day in, day out. And if you've been in a hospital you soon realize that even fully trained professionals aren't always very good at it. There's a reason why ~250,000 people/year die from entirely preventable hospital mistakes, and one of the big ones is hygiene. When done properly mask wearing is very helpful. When done improperly it can actually make things worse than having no mask at all. Most of the "unwashed masses" appear to be doing it improperly--even those who have good intentions! I don't have good mask hygiene. Just call me "Pigpen". The purpose of a mask is to filter stuff out. If it's doing its job, it will have virus particles on the outside. Then you handle it and you get those particles on your hands. And then you get them on your face when you take your mask on and off. And whatever you wiped from the grocery cart onto your hands ends up on your mask when you adjust it or have to scratch your nose. Then you wear those germs around on your face for a nice long time so you can breathe it in for extended periods in a nice moist environment where germs particularly thrive. I've been a fidgeter and nail biter for 42 years. Heck, I still pick at my underwear. I should've been a baseball player! No, but I can deny that the scientific studies are based in reality. They're based completely on ideal situations and make the erroneous assumption that everyone is masking correctly when in real life, nothing could be further from the truth. You know how many masks I see wrapped around grocery cart handles on the way to the store?? People take them out, grab a cart with their mask still in their hand, then put it on just before they walk into the store. I have yet to see one scientific study that accounts for practical mask handling rather than the purely theoretical ideal we're supposed to aspire to. They need to start taking into account actual human behavior rather than some ideal that doesn't exist in the real world.