It's no secret that nobody likes creating documentation. I don't like it, and you don't like it, even documentation lovers don't like it. But while you can live without documentation, you really shouldn't. And I am not talking here only about documentation that is only useful in the onboarding process of new employees or documentation concerning introducing someone to some concepts to get them easily start. I'm talking about documentation for your live environment where you know what you have, how you have set it up, but is still the same after one week, one month, or one year? Usually, not so much. And one of the worst mistakes admin can do is assume that his environment doesn't change, things are as they were when they were set up.