That's not how your brain works. Me neither. I can't go longer than a few minutes tandem coding without going nuts. It's tortuous. I don't think like other people; I come at things backward or circle around and it drives other people nuts, too. Plus just the presence of other people is exhausting, and I can't even think. I don't code to produce software, I code to learn and explore. Same as with most things I do. (Probably ADHD related.) But clearly it works for some people.
8 hours a day pairing means that pairing is the default, but it’s not the only thing that ever happens.
also: 8 hours/day pairing meant 16 hours/day not working at all in my case. Really really really not working. Not checking Slack. Not trying out some crazy idea. Not working at all.
IM notification from an old teammate pops up complaining about my boss? Seen.
Switch to a window with my personal email and they can see that thing I just bought or that recruiter I've been talking to? Seen.
I type a stupid thing that will never work? In the 5-30 seconds before I realize it, seen.
It doesn't matter if I trust my pair. That's not how the brain works.