[douche]

Having the entire design of a system in your head is invaluable. I'm in that situation with one of the products I work on. It can be frustrating, at times, when there is more to do than one person can handle, and you have to delegate tasks out, so you end up spending much more time explaining how something works and guiding someone else as to how to implement a feature, than it would to just go in and make the necessary changes. Eventually, it does pay off, but it requires constant effort to keep abreast of the changes and document everything.