[btschaegg]

Well, it often isn't that simple, really. "Old" knowledge can also be simply not true anymore.

I've had discussions with "industry veterans" that didn't get the fundamentals about their machines straight (a couple of them, for example, seemed to be ignorant of the fact that caching is a thing and influences your memory access delays).

Usually, that wouldn't be much of a problem, except when they claimed authority on performance and how hot-path algorithms should be implemented. The upside to those discussions is that they're usually easily settled with a couple of benchmarks and unit tests.

Similarly, I'm often puzzled whenever I encounter someone who works on a ("official") C++ project and e.g. refuses to use RAII and/or const properly. I get that you might dislike to depend on too many "external" tools, but just throwing the upsides of the language you're using away because "that's not how we did it back in the day" really bugs me. I can't avoid the impression that those people are being willingly ignorant...