Pair programming is fundamentaly as simple as it sounds, but in practice it has many layers.
You know, one way to look at Agile is to observe that it’s simply an attitude that recognizes that software is done by real people who have complicated personalities. Tasks don’t get done just because they’re next up on the Gantt chart, they get done because a human person has his or her head together enough to think clearly and figure them out.
That’s the nature of creative work. Thus, you’ll often find that production doesn’t equal resources multiplied by time on task. If you care about your project, cultivate the conditions that help yourself and others do their best work. And pairing, done well, helps bring about such conditions.