[seancorfield]

Improving your skills is always relevant. I think The Pragmatic Programmer's advice to learn a new programming language every year is aspirational but still good -- I've tried to learn a new language every few years for the past couple of decades.

That's how I came across Clojure back in 2010 and I've ended up using it in production ever since 2011 and I consider it my primary language these days.

Given how nearly all mainstream languages have adopted features from functional programming languages, I definitely think there's value in improving those skills, and working with a range of languages that are functional-first, including immutable data structures, lazy evaluation, and so on. Mastering these concepts will make you a better programmer overall, regardless of what language is your day-to-day "home" because you will think about problem solving in a more diverse way.