It's a southern thing, I don't do it as an adult though, as a child sure, but as an adult, it's not really as cordial as it might seem, I would rather just stick to the please and thank you. Not every woman wants to be called "ma'am", they might accept that from a child because they don't expect them to know any better but as an adult there are more avenues to show respect beyond just highlighting the difference in age between you two. And for men, I don't say "sir", I just carry myself respectfully, fukk I look like calling another man sir, and why, just because he has been living longer?



, imagine the possibility of addressing a racist white man as "sir". 
I can't believe I have to explain this to grown ass adults though.