Yes. It's amazing how I can quick pick up my new job's random DSL and special secret sauce algorithm and know house toolchain, and fix bugs in them immediately,

Yes. It's amazing how I can quick pick up my new job's random DSL and special secret sauce algorithm and know house toolchain, and fix bugs in them immediately, whereas 10 years ago I was mindblown for weeks trying to understand how he Y Combinator and call/cc where even theoretically possible. Same with pointers before that, and the whole concept of a computer program drawing a picture on the screen before that.