Rude people

When did "UH" or "Yep" replace Hello? When I go to the Niagara Falls Public Library there is one guy who answers with "Yep" when I say "Hello" or "thank you" . Before you ask, he is not a young man, he is an older gentleman who should have some semblance of being polite. The younger guy that works there always is so nice and polite. I am usually in the library once a week. This has been going on for months. I just wonder why a quick Hi can't be said.

And speaking of rude, yesterday I answered a knock on my door (not a ring of the doorbell right near the door) and expecting to see my niece, I instead see a salesperson (4 p.m. on a Friday after a VERY long and busy day at work). Although he tried to convince me he wasn't a sales manager and was giving away wireless security systems for "FREE" I told him I wasn't interested. When he asked me why and I answered him that I have a security system and that I don't buy things from door to door salesman. HE started to argue with me that he wasn't a door to door salesman and the system is FREE. I did finally just close the door on him...I hate pushy salespeople and I really dislike people who think because I look young they can talk to me like I'm stupid.