When I read this I was thinking that I didn’t say Shannon couldn’t do it, but then I read what I wrote, and I saw that I did say that. That was a writing error, unless I’m misremembering what I thought. I thought he probably could do it in his head, but that it wasn’t automatized enough to where it would be more convenient to do it in his head. That doing it in his head would be too mentally taxing or unreliable. And I thought that would be analogous to this:
Like why I assume 2 by 2 multiplication in your head is required for arithmetic mastery by your standards? I think that would come from mastery being emotion resistant, which for multiplication would translate into it being more convenient to do in your head.
When I first wrote about the Shannon quote I didn’t think through it that clearly, although I think I can remember thinking about emotions and mastery, that just seemed like fitting your standard.
I wasn’t looking for examples of great mathematicians not having mastered arithmetic, I just stumbled upon this text. But it could be that I’m biased toward finding such examples and thus I would think that this Shannon quote would contradict your standards of arithmetic mastery without clear ideas of what your standards would be.
Anyways I was interested to find out if you don’t consider habitual 2x2 multiplication in your head necessary mastery for mathematicians. Do you?