More pet peeves?

I just feel compelled to talk about an issue that has been bothering me for a little while now. You know how people are different than you? There is this one type of person that really bugs me and while working in a music store I run into them often. If any of you have had experience in customer service or cashier-type jobs then you've probably run into this person too. One of them came into my work today.
They are the type of person that seems oblivious to everything. I ask if they are ready to check out and they mumble 'uh huh' while not making eye contact. I actually had one woman look the other way and shove her books at my face. Needless to say I waited politely for her to place them on the counter. This type of person is almost always a woman, except in one case where it was a man. He bought religious books and was accompanied by a girl and a dog in a stroller. That's what I said. A stroller. He slammed his books down, faced away from me and started picking something out of his finger nails. I instantly think... who died and left you king.. or queen? I just don't understand this type of person, why is it hard to make eye contact? Why is it hard to form complete sentences when being asked "did you find everything ok"? These types of people will wander the store looking for the 'check out' and upon finding it will exclaim, well I just wasn't sure where I was going! (Hard to believe since I greeted them, helped them find their books, and then told them I'll be in the back when they are ready to check out). This type of person revels in their stupidity. This type of person always acts like the amount they are paying for their music could hardly make a dent on their credit card, and yes, it's almost always credit.

I don't really like going through check out lines myself and will usually ignore all the familiar banter, but I make eye contact. I don't tap my nails on the counter, I don't sigh when it takes just a minute too long and I don't pretend like I have no clue what is going on when someone says "your total is....". I do have to admit that when I'm in the Walmart Neighborhood Market I chose the line where you can check yourself out just so I don't have to deal with people. You see, I chose to not deal with people because I'm self sufficient. That's how I like to look at things.