When I first started working as a programmer in the early 90's, I was surrounded by older guys whose advice was always along the lines of "hoard information and knowledge, make yourself indispensable/unfireable". It seemed like silly advice to me at the time - surely as long as I was doing good work, I'd be recognized/rewarded, right?

Yeah, after a couple of decades in this meat grinder I realized they were right: the best survival skill is to just know a lot of stuff that nobody else knows.