My daughter from my first marriage turns 10 next week, and more than a few times she's called from her mom's house right after school, saying some kids teased her for saying "Yes Ma'am" to the teacher, or "Yes Sir" to the Principal. I always tell her to not mind what they say, and praise her for showing respect.
Our oldest boy, Ronan, is 3 now, and folks around home think it's so cute when he says "Sank-you, Mam". But, when you go into the city, and say that in a restaurant or something, people look at you as if you're an alien. I've actually had waitresses ask me not to call them 'Ma'am', because it makes them feel old. They haven't witnessed proper manners and respect in so long, they can't even recognize it when it comes in a complimentary fashion.
As far as I'm concerned, the world would be a far better place if everyone acted more like Greg and a few others. Open doors for anyone, tip your hat, speak your manners, and show those random acts of kindness at every opportunity.