Excellent point. If my seat belt is working, what difference does it make if you wear one or not?
If yours is working, what difference does it make if I wear one or not?
Hmmm...how many patients in surgery are required to wear masks? Could it be that the doctor's masks are sufficient? If...
Could you give us a link to your claim? I have been looking at solar energy since 1974. It was not cost effective then, and it is not cost effective now. If it were a viable source of energy, you'd have SP sales people on every street corner.