Thanks! Macroexpanded:

Matrix Multiplication - https://news.ycombinator.com/item?id=24141472 - Aug 2020 (1 comment)

Matrix Multiplication - https://news.ycombinator.com/item?id=13036386 - Nov 2016 (131 comments)

Matrix Multiplication - https://news.ycombinator.com/item?id=13033725 - Nov 2016 (2 comments)

Interesting to compare this discussion vs the discussion 5 years ago. Although the consensus is the same (that it's not very intuitive) people seem to be much more blunt with their criticism now...