The plain fact that I'm quite ignorant!
And did you see the staircase connections? Amazing!
I guess that electrons accumulate in the corners, like plancton in a squared pool. I just wonder whether they die as it happens to jellyfish... (I discovered that in a backstage tour of a nice acquarium)
Beside the nice talking, a good mention goes to an interview to dr. Howard Johnson
Around time 1:15:00 of the podcast he finally gives a great answer on why 90 degrees tracks aren't an issue (for most of us).
But the great part is where he explains how that enormous misunderstanding has grown and propagated -- finally a funny fact that quenches
my thirst for knowledge in an easy way!
Spoiler: it all began with people working at 50 GHz and 120 mils(!) traces, with multiple stage amplifiers. For them, that added 0.4pF on each corner is an issue. Even working with 10 mils traces is a so ridiculous contribute that can happily be forget.
Now I can sleep well, knowing I won't dream of electrons bouncing in the corners anymore