Number One: Imagine a world where CDs are still among your prized possessions. You file your CDs in alphabetical order. You have the entire catalog for a band - do you arrange them alphabetically by title, or chronologically according to release? Why?
Number Two: You're going to see four moderately well-known bands play. One is your favorite band, one is a band you can't stand. Is "Never wear a band shirt to a band’s concert" a hard and fast rule, or in this case, is it ok to wear the t-shirt of the band you're going to see? Why?
Number One: Chronologically, of course. The collection as a whole is arranged alphabetically, which is enough to satisfy my OCD side. But I like listening to bands from the beginning, to hear how their music progressed. Also, I started filing my music this way before we had the Internet at home, so I was able to go to my cabinet and see what order albums were released even though I lacked constant access to Wikipedia.
My CD catalog.
Number Two: I wear a band's shirt if they're playing in a festival environment. I want to show my support, and when I've done this in the past, the bands are "small" enough, popularity-wise, to notice and appreciate it. And God forbid someone assume I'm there because I love the headlining band if they truly suck. I don't see the big deal about wearing a band's shirt to their show - who really gives a crap about that kind of thing? If I were a rock star, I'd love seeing my logo out in the crowd.