16. They're not smart.
19. You're not smart, either.
Assume everyone is an idiot, including yourself. Verify everything (your own work and other people's work) using robust testing protocols. Don't use your own judgement; you're not smart enough for that. Gather evidence. But test your evidence-gatherers to make sure they're doing their jobs, too. Assume every component of your system-of-people is half-fallen-down and just barely limping along at all times. Make a system that works in the face of everyone coming to work with a concussion.
(And, if some component isn't barely limping along, then people are probably being too naive about its potential failures, so inject some chaos [monkeys] into it to get its reliability down to a level where routing around it has to be operationalized, too.)
Similar idea from another angle: superficial design flaws obscure fundamental design flaws (Douglas Adams on the Sirius Corporation Complaints Depatment)
“Chesterson’s fence”
https://en.m.wikipedia.org/wiki/Wikipedia:Chesterton%27s_fen...
Once I have seen a project manager who's project didn't deliver much insight, so he had this brilliant idea to advise to replace some software which was built with some old technology. He didn't have the slightest clue how that software worked, he just knew what the purpose of the software was and his advise was to rebuilt it with newer technology to make it better (whatever that means).
When I told him, that the software wasn't as trivial as he might think and that I am against replacing it, as long as it wasn't clear how the new version would be better (besides being built with that new technology he was suggesting) he started looking for some other findings his project could deliver.
>19. The odds are greatly against you being immensely smarter than everyone else in the field. If your analysis says your terminal velocity is twice the speed of light, you may have invented warp drive, but the chances are a lot better that you've screwed up.
Learning how to better thread the needle between these two is been one of the most important things I have learned in my career. Just because this is the way it was always done doesn't mean we have to do it that way, but the people who did it that way probably had some reason for it that is worth exploring and fully understanding.