I did when I was a kid. As I got into teenage years, I eased off of it a bit, although I did use it when circumstances called for it. This was usually after I had screwed up. 🙂
To me, it goes with another thread I just saw on here where someone asked about calling teachers Mr/Ms and their last name. It's respect, pure and simple. I dunno, maybe it's just a Southern thing.
Sadly, I never got to find out how things would be different as an adult, since my dad passed away when I was 18. With my mother, I dropped the ma'am as I hit the teenage years. I don't really do it with my stepfather, but then again, I was 30 when he married my mother.