Also, about algorithms, I walk through them a step at a time, keeping track of where things are in my memory. :) Once upon a time I could play an amateur level game of blindfold chess the same way. It never occurred to me that when Walter Browne was playing blindfold chess for money on the beach at Santa Monica before the 1976 US Open, with money and time odds 5:1, that he could actually see the board. I'm less impressed now, but was nowhere near his level anyway even if I could see the board.

Your memory is better than mine. I work from an abstract level downwards in a "how would a machine that does this thing work" sort of way, decomposing the machine into parts as I go. Interesting how different people have different approaches.

What you say about white board exercises is interesting. Maybe I just don't like them. :)

on a related note

http://nautil.us/blog/why-blind-people-are-better-at-math

It seems that I'm better at doing math in my head than most people. I've wondered whether that might be related to aphantasia.

That is interesting. I'm pretty excellent at math concepts in general (750 SATs in math once upon a time) but can't do arithmetic in my head to save my life. It wouldn't surprise me at all if there's a relationship there, especially for processes like multiplication or long division where you have to hold an intermediate result.