A beginner who couldn't code and took on freelance work with AI looked back on his first project: whenever there was a bug he'd just say "something's wrong here, fix it". The AI fixed one spot and broke another. He didn't know git, and didn't know code could be returned to a previous version, so all he could do was keep asking the AI to fix, and it got messier every round.

The first habit he learned afterwards: every time you finish an important feature, save a version that runs correctly.