This how I learned various technologies. I often re-implement my personal invoicing system (I'm a freelance copywriter) in whatever technology I am interested in: i) PWA with a react front-end, ii) AWK-based invoice processing iii) massively overcomplicated system based on Elixir and Phoenix Liveview, etc. I've also done something similar with a personal flood monitoring app (I live near a river prone to flooding). I'll never be a real developer, but it helps me to understand the technologies a little and know when they might be useful for something I want to make.