I know what you mean. I know a guy who attends the college I go to, and he is the brother of one of my friends, who also goes there. Anyway, his name is
Andrew, but everyone calls him
Drew, even his brother, and he goes by that himself. Most people I think do that because they simply don't want to say the full name. They're used to shortening it, so they shorten it. I know one guy named
Daniel and he doesn't shorten it at all.