You might suspect that given a world where context is constantly shifting, your nerd can’t focus, and you’d be partially correct. All that multi-tasking isn’t efficient. Your nerd knows very little about a lot. For many topics, his knowledge is an inch deep and four miles wide. He’s comfortable with this fact because he knows that deep knowledge about any topic is a clever keystroke away.
— Rands In Repose: The Nerd Handbook (thanks inky). I haven’t read the entire article yet, but I can already tell that I’ll be quoting it a lot. If you like Rands, you should support him by buying his book.