Hell, you can experience it first hand as a programmer. I could technically work on any programming job, from databases to JavaScript to game engines to machin

Hell, you can experience it first hand as a programmer. I could technically work on any programming job, from databases to JavaScript to game engines to machine learning, just like a lawyer could technically be any type of lawyer. But it is way, way easier for me to get a job doing the exact same type of programming I've been doing for the last decade, in the same environment, and I get paid way, way more to do that, because my specific experience makes me so much more valuable.