Tell me why people no longer say thank you...

I can't tell you how many times this week that either my son or myself have held open a door for someone, only to have them walk right through without so much as a glance our direction! Sometimes I just think that maybe it's not "in style" to say thanks anymore, but then I see that my son and his friends are still using basic courtesies, so it can't be totally "uncool".

It's not an age thing either. There are just as many middle-aged and older folks not saying thanks as there are the younger generation. Has it just become second nature to be rude to people? Are people just expecting that someone should be polite without expecting a thanks in return?

Tell me why....