I was always taught, safety is an obvious but as for the one guy that always seems to have a better way to do things and push that way on you, well i just dont want to be "that guy". I had a guy come in my hotrod shop and tell me about what a waste it was that i put new gas tanks in all my cars i build, then a year later i find out right after he came to my shop he started a build and decided to weld on a "cleaned out" gas tank...needless to say he is not with us anymore.
I have always tried not to be a jerk about it though when painting cars but still let people know #1 as all you guys said, wear a respirator. My brother was car painter ever since i was little. Back then he had an iron grip but years of that old toxic paint left him barely able to hold a soda can, then he got white matter brain disease and died. And #2 i am truely shocked how many people go to paint their car in their garage (must have more tolerant wife than i) and decide to use whatever old fan they can find to blow out the flamable overspray and fumes. When i was out west, at least once a year some guy would blow up his whole garage. I hate to see any of that happen to anyone.