I got my start in professional software development by building an multi-user Access shadow-IT database application that made heavy use of VBA. It only worked because it had a couple of active users at any time, and I left that workplace with documentation consisting of a half-page of bullet points. I know for certain that it was still in usage four years after I left, though God know how long it kept operating in the end.

Notwithstanding that shadow IT is the bane of my existence these days, I sometimes need to be reminded of how far a motivated individual can come when they have access to adequate tools and information.