He missed: Learn how to read code, and read lots of it. Also: Find someone who knows how to debug, and sit next to them for an hour or two while they tear apar

He missed: Learn how to read code, and read lots of it. Also: Find someone who knows how to debug, and sit next to them for an hour or two while they tear apart a problem, fix it, and make sure it's solved. I've had a couple of tough sessions with world-class debuggers, and learned an amazing amount in a very short while.