People will think you are exaggerating, you aren’t. They will also think I’m exaggerating that you aren’t, I’m not. Learning about capability-based microkernels and realizing this has been a solved problem for years, and is actually one of the rare easy freebie problems in computing, is a highly sobering experience!

Only thing I disagree on is that we lost that knowledge, we did not, there isn’t much to capabilities, they actually simplify OS design IMO.