Why do unusual jobs and code updates still catch me out?

You've trained yourself on the routine work, and it no longer scares you. That's real progress — don't dismiss it. But the unusual job exposes what your training never covered, and the code update exposes what changed while you weren't watching. This doesn't mean you're unfit for the work. It means your system for staying current stops at the familiar. Most people build skill through repetition and let everything outside that repetition go unwatched. You are not the exception — you're the rule, doing what everyone does until it costs them. The fix isn't more studying in general. It's specific: a habit of checking for changes before you need them, and a written method for the job you've never seen, so you're not guessing in the moment.