What makes nerds “nerds†is that they care to an irrational depth about certain specific things.
I’ve always felt like this was the basic idea behind what it is to be a nerd. All the trappings about computers, Magic cards and Dungeons & Dragons (stamps, movies, music etc.) really just comes down to a focus on details. It’s great to find a definition that sums you up in a few words.
The quote is from Daring Fireball, which is really only about Apple and Macintosh but somehow manages to be a great read all the time.
http://indianapolismonthly.com/monthly/article.asp?articleID=3