I just bought my very first mac and am going through setup. I notice already that the name appearing under Macintosh HDD does not match the user name I specified during setup? Is this the short name I've been reading about? Can someone explain to me what the short name is, why it's different than the user name? Also, is the user name the same as the home directory name? I'm confused by all these "names" i've been reading about. Thanks!