Yes and no. I'm very glad that I followed the Pragmatic Programmer approach early on in my career. It's partly why I learned Ruby back in 2003, and was exposed

Yes and no. I'm very glad that I followed the Pragmatic Programmer approach early on in my career. It's partly why I learned Ruby back in 2003, and was exposed to Lua and Haskell and others around the same time (and built pretty neat production software in all of the above languages) Over time it becomes less necessary to deep dive on new languages, but that doesn't mean you should altogether stop, it just means that you're more of an expert now and learning a new language to the point of mastery that you are used to in your day to day work is a lot bigger task. What the author describes is the dilemma with any kind of knowledge acquisition. You always need to be learning more, but you have to balance that against being productive with what you actually know. As an expert or senior or whatever, I have a pretty good understanding of what the knowledge landscape looks like. As a junior there's a lot more utility in doing a broad survey before diving too deep.