Yes, that does sound familiar. I've never done pair programming, but I have the feeling I'd have a lot of the same problems as the OP. I'm very much an introvert, and even just our open-plan office sometimes has me wanting to shut myself away by the end of the day. And the more code I write, the less English I seem to speak, especially to describe code. I wind up either flailing my arms and speaking gibberish (only a mild exaggeration) or just giving up and writing pseudo-code because I just can't express the concept any other way. English just isn't precise enough.