I've been thinking about a class of related phenomena recently: those where a one-to-many relationship leads to inappropriate feelings or behaviors. I'll give a few examples.
Often, some shared cultural item (The Chronicles of Narnia, Amsterdam, Ernest Hemingway, chopsticks, etc.) comes up, and I feel as though I have a special relationship to it. I want to impress upon others my special relationship, to tell them the stories about myself and the item. And then I realize how extremely common it is for someone to have specific personal memories of reading a popular book series or using or watching others use chopsticks or whatever. Just because I visited Holland in the mid-90s doesn't really mean I have a special relationship with the country.
Professors commonly get a lot of annoying emails from their students. If you think about it, a student generally has at most five or six professors at a time, while a professor may have anywhere from 20 to several hundred students. Three or four emails per semester to each professor is easily manageable to the student, and overwhelming for professors. Students also feel that their own experiences are more unique than professors find them to be.
There are a few well-known blog authors whose blogs I have read for years. (John Scalzi and Andrew Sullivan, for instance.) I feel like I know these bloggers, have a sense of their personalities and experiences, etc. If I saw one of them, it would be easy for me to assume some kind of mutual familiarity that does not exist at all; they don't know me from Adam. I think people often have this feeling about celebrities.
Of course, it is always tempting to regard one's own experiences and situations as unique and special anyway, given that one's world revolves around oneself. But I do think these one-to-many situations, where something is more unique for you than you are for it, are especially prone to provoking such feelings. Perhaps this is why people like to have known indie bands before they became popular; it makes their special relationship to the band more plausible because it existed when the many wasn't so multitudinous.