The gist of it:

We are constantly faced with problems to solve and decisions to make. A helpful tool when faced with multiple tasks at hand is to ask yourself:

What is the one thing I can do that will make everything else easier or unnecessary?

This helps unpack and prioritise the tasks at hand and determines the right sequence to do them in order to achieve maximum results with the least amount of effort.

How to use it:

Say you want to be healthier and to do so you would need to eat better, get enough sleep and exercise.

However, in reality you are facing a cycle of regular sleep deprivation which causes you to lose focus during the day.

This would result in having to stay up late to catch up on work, often snacking in the night in order to have energy to work.

And that would usually mean you wouldn’t get enough sleep, which would make you tired the next afternoon, causing a craving for sugary foods to keep you going through the day.

This whole cycle perpetuates and by the time you finish work, you are too tired to even exercise.

The simple fix to all this is to sleep earlier (the one thing). When you sleep earlier:

You have control of the number of hours you sleep, instead of letting the time you have to wake up determine how much sleep you get. > Get more sleep

Because you slept earlier, you wouldn’t have to snack at night to keep yourself awake or snack on sugary foods during the day to keep yourself going. With better control on your cravings, you can make more intentional choices on your diet. > Eat better

By sleeping earlier, you could then wake up earlier to exercise before your day starts. > Exercise

By identifying and triggering the key domino block (Sleep earlier), you are now able to achieve your objective (be healthier) by making the rest of the tasks much easier to do.

Level Up

Another way to frame “The One Thing” is to move decision-making upstream by asking yourself:

Where can I make a single decision that will remove many decisions?

The idea here is life becomes easier when you make one big decision that can be replicated over and over again.

We rarely face truly unique one-off-decisions and there is an overhead cost to any good decision; it requires argument and debate, time for reflection and concentration and you need to expend energy to execute. So given this overhead cost, it’s far better to zoom out and make a few big generic decisions that can apply to a large number of specific situations - Jim Collins

Are there specific situations in your life that you can create a blanket policy that helps you make quick decisions?

Here are a few examples:

1. Define the things that you won’t invest in

There are infinite investment choices available and we will always be tempted to change our portfolio, strategy or asset allocation. Investors are constantly inundated with new funds, market opinions and recommendations. It is virtually impossible to sift through all this noise to make an information decision. At the same time, we risk FOMO and hard to control emotions that make us go against our own personal interest. It’s best to stop trying to figure out if every investment option you hear about is right for you and instead just define what you will not invest in (e.g. specific investment vehicles, types of companies/industries etc).

2. Figure out the types of people you won’t be friends with

The people we spend our time with have a huge impact on our behavior, attitude and overall outlook of life. At a certain point, you will start having less patience for the negative people in your life. You know exactly who these people are and you should make it your goal to purge them from your life as much as possible.

3. No coffee meetings / no meetings without a clear agenda

This one is slightly contentious (and may not be possible for everyone) but some productivity folks have sworn by it. We all know pointless meetings are a huge time suck and so one way to manage this is to have a blanket rule to not do any coffee meetings or attend meetings without a clear agenda.

4. Always sleep by [Time]

Research studies have shown that a regular sleep schedule has huge health and performance benefits. By setting a time you will always sleep by, you make it a point to say no to everything unimportant that could keep you up after your bedtime. Want to watch an additional episode on Netflix? Nope, it’s time to go to sleep.

Don't make a hundred decisions when one will do - Peter Drucker

Sources:

The Power of Making One Decision That Removes Hundreds Of Small Decisions.
17 questions that changed my life