I had a coworker with whom I did some pair programming and it was painful. He was very talkative, to the point of forcing me to interrupt him every time to come back to what we were doing. Also most of the time he made really hard to follow the code because he took every opportunity to show off his keyboard-shortcut-skills, jumping from file to file, jumping between lines of code, commenting and uncommenting code... all that very fast.
2) You'll pick up his shortcut fluency in about two days of pairing ... I taught my co-founder Emacs and Clojure at the same time in about two days of pairing
This describes every pair programming session I’ve ever had in 15 years and 5 companies. And I’m sure I’m guilty too. Pair programming occasionally helps, but as a frequent practice it causes systemic harm, especially to morale.