[Question] Another case of “common sense” not being common?

Okay, that is probably not that good a characterization. However, I do like when someone figures out a simple way of looking at problems that have gone unsolved and so thought to be very difficult, so therefore must be really complicated.

If you didn’t see this:

https://​​www.quantamagazine.org/​​mathematician-solves-computer-science-conjecture-in-two-pages-20190725/​​