Most years I choose a language I've never worked with commercially (e.g. Fennel in 2022) and rather than reach for prebuilt libs for timesaving fancy array or set or string ops, I'll invent those wheels myself without dependencies and I find a ton of satisfaction in it. Unwise commercially but ideal for learning and play. And, yeah, bugs!

IMO, when it's not a customer paying for my learning curve, there's a lot to be said for rewalking old paths with new boots (or no boots and funky coloured glasses). Also, a terrible way to get onto the leaderboard IME!