A system to organise your life

Johnny.Decimal is designed to help you find things quickly, with more confidence, and less stress.

You assign a unique ID to everything in your life.

A diagram showing the structure of a Johnny.Decimal number. The number is 15.52 and it explains how the '1' is an area, which groups related categories in sets of 10. The '15' is the category, in this case 'travel'. And '52' is just an ID; they start at 01. The title of this, our 52nd travel thing, is 'Trip to NYC'.

These IDs help you stay organised. They impose constraints that make it harder to get lost. And you create your own index to link everything in your life together.

The system is free to use and the concepts are the same at home, work, or that club you manage.

The problem

In real life, if you stored your stuff in piles of badly-labelled boxes you'd never find anything again.

If you put those boxes in boxes, in boxes, you'd never know which box to open to find the next box. It would be chaos. But this is how you save your computer files.

A screenshot of a MacOS Finder window showing a bunch of folders, nested terribly, all named similarly. It's a confusing mess.
FIGURE 11.01B. A CHAOTIC FILE SYSTEM WITH MANY LEVELS OF FOLDERS.

The solution

Here's one way to think about how a Johnny.Decimal system works. In this simple analogy, an area is a shelf, a category is a box, and an ID is a manila folder.

Step 1: Buy ten shelves

Imagine a computer is a garage. We can't put everything on the floor, so we buy ten shelves. Then we dedicate each one to an area of our life -- life admin, home business, and tennis club.1

A line drawing of three storage shelves. Think your classic Ikea 'Billy' bookshelf. At the top they're labelled 'life admin', 'home business', and 'tennis club'. They're empty.
FIGURE 11.01C. A SHELF FOR EACH MAJOR AREA OF OUR LIFE.

Step 2: Add some boxes

Each shelf has space for ten boxes, so we categorise what we want to store. In life admin we decide on five and label them: me, house, money, online, and travel. Our boxes have space for a number, so we add that too.2

The same shelf and boxes, but now the labels have numbers at the front. The shelf is labelled '10-19 Life admin', and the boxes are labelled '11 Me', '12 House', '13 Money', '14 Online', and '15 Travel'.
FIGURE 11.01D: OUR LIFE ADMIN SHELF ENDS UP WITH FIVE BOXES.

Step 3: File your stuff in folders

We put our documents in manila folders. Each folder gets a number starting at .11 so we can track them. In this case, we've put some insurance policies in 15.23 Travel insurance. Then put the folder in a box.

Line drawing representing a manila folder. It's labelled '15.23 Travel insurance' and contains 3 documents, labelled 'Claim form', 'Payment receipt', and 'Policy document'.
FIGURE 11.01E. WE PUT OUR DOCUMENTS IN NUMBERED FOLDERS AND STORE THEM IN THE RELEVANT BOX.

This is how we structure our file system

Let's return to our computer. The shelves have become our area folders. The boxes are category folders. And the manila folders are the IDs where we save our files.

Screenshot of macOS Finder. It shows a parent folder '10-19 Life admin', labelled 'SHELF'. It contains folder '15 Travel', labelled 'BOX'. And it contains '11.53 Travel insurance', which is labelled 'FOLDER'.
FIGURE 11.01F. A NEAT FILE STRUCTURE WITH AREAS, CATEGORIES, AND IDS.

Benefits of the Johnny.Decimal ID

Each of our storage folders now has a number, the ID. It always has two digits, a decimal, and two digits. For example, 15.23 22.11 31.17. This number is really useful.

It provides structure

The ID tells us exactly where a thing is. The numbers before the decimal are the item's category, and they define the structure of your system.

At a glance, you know what sort of thing the item contains. You'll be astonished at how many of your category numbers you remember.

They're easy to communicate

They're short, memorable, and can be spoken out loud. Say it like "sixteen oh-two" or "thirty-one dot seventeen".

This is really handy when you want to tell someone (including your future self) where a thing is.

Things stay where they are

If you use the alphabet to name folders, they move when a new one is created. So you never get a chance to develop muscle memory.

Numbers solve this problem. In the example above, 11 Me comes before 12 House because the folders sort by number. If we made a new folder, 16 Aardvark collection, nothing would move.

It imposes limits

The 'no more than ten' concept is at the heart of Johnny.Decimal.

When you start looking for something, you have no more than ten area folders to choose from. Select one and ignore the rest. Now you have no more than ten category folders to choose from. Repeat the process.

You then arrive in a folder with no more than one hundred IDs. If the ID was created recently it will have a higher number. If not, lower. And things created together, stick together. The alphabet isn't around to ruin the party.

I like it! What next?

Welcome to the Johnny.Decimal family, there's plenty to go on with:

Footnotes

  1. We don't try to use all ten shelves -- there's room to grow. ↩

  2. I'll explain later why the first box isn't number 01 or 10. ↩

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