Common Courtesy

Is is soooo difficult for people to have a little common courtesy?!?! I am courteous to everyone I come across, but I am finding it more and more difficult to find others that are the same, especially at the office. Some people say it is the twenty-somethings today, they have no regard for others. I have always been polite or friendly. It really doesn't take that much effort. In fact I would feel a little ridiculous just letting go ofa door once I pass through, especially if I know someone is following not too far behind me. I say hello or smile to those passing me in the hall - obviously we work together, even if you don't exactly know who I am, we are co-workers nontheless. And even better, you don't know who I could be or who I know. Doesn't it just make more humankind sense to say hi. Or just nod - acknowledging my presence is enough for me! I didn't just turn this way either, I have always been like this.