I also love pair programming. It usually begins with about 5 minutes of joking around and wasting time, but it takes only a minute or two to achieve flow. Indi

I also love pair programming. It usually begins with about 5 minutes of joking around and wasting time, but it takes only a minute or two to achieve flow. Individual programming can take 30 minutes or more to achieve flow. Once in flow, it is much harder to come out of it because you aren't tempted to browse to Hacker News. Also, no one will stick their head in your office and bother you because it looks like you are in a meeting. Partners are incredibly helpful spotting errors and act as an extra cache for all the little details you need to keep track of. Usually the person not typing has a lot more capacity for those details because they don't need to spend the energy operating their editor and manipulating code (no matter how good you get at it, it still requires some brain power: a limited resource). Also, when all is said and done, you now have TWO experts on a topic. Redundancy is a good thing.