Why do people stop your reading to ask....

What are you reading? If I'm engrossed in a book, I am obviously not intent on interacting with you, so why do you feel the need to interrupt me? Do you really, truly care what I'm reading? Are you going to run out and buy the book? No, every time this happens, the person wants to tell me about THEIR favorite book or author. Um...I don't care. I didn't ask and really do not care. I read what I like. I know how to find new authors (browse the library on a slow Sunday). I, very much, like to read while eating my lunch. It's 30 mins of ME time completely without anyone else. I really hate it when someone interrupts that little time I have.