I have gone from writing impulsive untested spaghetti code to using DDD, CQRS, TDD, and linting to aim towards making maintainable code. I didn't really get it before, but after trying to maintain a huge messy project for a few years I have now come to really appreciate this new style of coding. I can now look at my code and feel confident about changing it and that if I come back to it later I'll have a real chance of maintaining it without want to scrape that's there and rewrite it.