Ironically, mere exposure to data is enouhg to learn from in ML, so why not here. Although, I'm not sure about the pedagogic aspect. I'd assume calculation by heart would be learned along the way, despite sending the initial message, it wasn't needed. Maybe starting slow is important, because it's that fundamental. But in hindsight, I really was good after half the elementary training.
I have a similar anecdote: I wasn't good at handwriting and always claimed I wouldn't need to. Now I don't need to, indeed, except for exams. But I actually have a hard time with caligraphy and that's a shame.
Your anecdote is irrelevant because there is no _understanding_ to be gained by handwriting as opposed to typing.
I really can't be bothered with this conversation, sorry.