Just my opinion, but there seems to be a psychological effect to wearing a mask. It makes you more conscientious of your breathing and it prevents you from incidentally touching your face. That, and I feel much less need to shave...
BTW, much reduced line at the grocery store today compared to the last few times I was there. I stood at the front of the line for a while finishing my coffee before going in — actually I was the line, no one in front or behind. Once inside I found the shelves mostly stocked (still no peas), but the quantity limits had been lifted. I guess the panic buying is over.
Now we wait for HD to restock N-95 masks... oh yeah, 3M is feeling some heat...