In short: Only organize your notes/emails/todos/files when search is not enough.
My life, like everyone's, is full of concepts to remember, tasks to complete, and projects to manage. My emails, tasks, and notes have been powerfully organized with tags, sub-tags, sub-sub-sub-tags, and worse. Because of this rabid digital organization, I’ve never missed a deadline; I hardly procrastinate; I never lose a single note.
While my organization is definitely helpful, my reliance on it as the exclusive tool for success is a mistake. I am working hard on organizing and less on "deeper" work.
I recently purged a good deal of this organization in favor of simplicity. My new philosophy: organize what search cannot find, and nothing else.
For example, I stopped tagging all of my passwords with the "Passwords" tag. When I want to find my password for something, I can simply search for it and find it. However, I continue to tag my ideas, because I often like to browse those without looking for a particular idea. Search cannot help me browse my ideas; it can help me find my passwords.
This makes me have to remember *far *less about the confusing organization and focus more on the content.