When the right task becomes the wrong choice
One of the biggest mistakes we make is assuming our ability to think remains constant throughout the day. It doesn’t. Our mental energy rises and falls. Yet we often choose tasks as though every hour is equally suitable for every kind of work. It isn’t.
Some tasks demand far more mental energy than others:
- Planning a project.
- Breaking down a complex problem.
- Designing a presentation.
- Writing an important proposal.
These activities require deliberate, sustained thinking.
Other tasks require much less mental effort.
- Replying to routine emails.
- Booking tickets.
- Paying bills.
- Organizing files.
These rely more on familiar patterns and routines.
Daniel Kahneman described two broad modes of thinking: slow thinking and fast thinking. Slow thinking is deliberate, analytical and mentally demanding. Fast thinking is automatic, familiar and requires much less effort. Most knowledge work involves both. The important question is not which mode is better, but when to use each.
The common mistake lies is doing the right task at the wrong energy level. This leads to what I call The Energy Cascade Principle:
As your available energy changes, consciously choose the task whose energy demand best matches it.
Notice that I haven’t mentioned any particular time of day. That’s intentional. Everyone’s body clock is different. Even for the same person, energy varies from one day to the next depending on sleep, stress, health, exercise, or circumstances.
The question is never:
“Is it morning?”
The better question is:
“How much mental energy do I have right now?”
Whenever you find yourself at a high-energy point—whether that’s after a good night’s sleep, after an afternoon nap, or simply during your natural peak—invest it in work that requires slow, deliberate thinking.
As your energy gradually declines, let your work cascade toward activities that rely more on familiar routines and fast thinking.
One of the hidden benefits of this approach is efficiency. We often think of efficiency as using better tools or finding faster ways to complete a task. But there is another kind of efficiency: matching the task to the mind that is performing it.
A planning session completed at your mental peak may take half the time and produce a better result than attempting the same work when your energy is depleted. Conversely, routine administrative work rarely benefits from your sharpest thinking. Doing the right work at the right energy level is one of the simplest ways to improve both productivity and the quality of your thinking. Once you begin noticing your own energy patterns, task selection becomes much more intentional.
The pioneering neurosurgeon Wilder Penfield observed:
“The best rest for doing one thing is doing another until you fall into a sound sleep.”
That insight is profound. Recovery doesn’t always mean stopping. Often it means changing the kind of effort.
After hours of strategic thinking, reading may feel refreshing. After writing, organizing your notes may be relaxing. After solving difficult problems, a walk, gardening, cooking, or exercise may restore your mind. You’re still engaged—but you’re no longer asking your brain to perform at its highest level.
But Don’t Let the Mind Go Completely Slack. Relaxing is not an invitation to spend the evening in mindless distraction.
- G. Sertillanges, in The Intellectual Life, captured this beautifully:
“Yes, indeed, relaxed; but like a violin with all its strings completely slackened. What a labor next day to tune them all up again!”
Recovery should keep the mind gently alive. Reading, Learning, Meaningful conversations, Music, Hobbies require less energy while still engaging the mind.
The goal is not to maintain the same energy throughout the day. That is impossible. The goal is to consciously match your work to your changing energy. As your available energy changes, transition naturally to work requiring less mental effort and supported by greater intrinsic interest. By the end of the day, you aren’t forcing yourself through difficult thinking, nor have you abandoned your mind to passive distraction. Instead, your day has flowed naturally—from demanding to lighter, from analytical to enjoyable, from intense concentration to gentle engagement. Like water descending a mountainside, your work follows a natural gradient.
When you match the energy demanded by the task with the energy available in your mind, work becomes more effective, more enjoyable, and far less exhausting.
Disclaimer
Views expressed above are the author’s own.
