I love organizing data, and offices (and all of my friends closets). Real work is messy; so it's nice to start and end with a clear palette. In this way, one creates a balanced office.
In my own filing system, I can find any piece of paper, from any year, within minutes. In the book, I explain how to create a filing system, even if you're starting with an office disaster. From that core system, you'll modify your filing system according to how you do business, so that you too can find any piece of paper in minutes. This is absolutely doable; I've done it for many clients. Here's one tip: it's rarely necessary to file a singe piece of paper. Put it in a "To Be Filed" folder. When you find yourself with a spare 10 minutes do all the filing.