As a person from the the U.S. I don't hear people say mister often unless in front of a last name. For example Mr.Dipasquale. A lot of the females I've met find ma'am very offensive .They think by calling them ma'am youre suggesting they're old. I can't wrap my head around this. I use the word sir to address a lot of people and hear it sometimes, but its usually said in the military