The important mental change, and it's a real challenge - is to realise that your knowledge of how the system works in your head is cache rather than live data,

The important mental change, and it's a real challenge - is to realise that your knowledge of how the system works in your head is cache rather than live data, and that you need to check the document for how to do it. So if you change something, you write it to permanent store, not just to the cache. Which means it's not the new way to do something until it's the way that's written into the knowledge base.