The Letters

The Most Expensive Things Are Free

By Seçil Sayhan, MSc Clinical Health Psychology & Wellbeing2 min readAugust 10, 2026

What’s in this article

  1. The pattern
  2. The mechanism behind it
  3. What to do with it
  4. The bigger picture
  5. Frequently asked questions

a founder i work with can move a very large amount of money in an afternoon and cannot leave a dinner before midnight. not because he's enjoying it — because leaving requires a decision, and he spent every decision he had by four o'clock.

The pattern

a founder i work with can move a very large amount of money in an afternoon and cannot leave a dinner before midnight. not because he's enjoying it — because leaving requires a decision, and he spent every decision he had by four o'clock.

everything on this list is cheap in money and expensive in the one currency nobody budgets: how many decisions you have left when it matters.

which is why "just have more discipline" is such useless advice at that hour. there's nothing left to be disciplined with.

comment ENERGY and i'll send you the energy rebuild — where the day actually leaks, and the three places to plug it first. free.

The mechanism behind it

Someone I work with can move a very large amount of money in an afternoon and cannot leave a dinner before midnight. Not because he's enjoying it — because leaving requires a decision, and he had spent every decision he had by four o'clock.

Being on time. Saying the hard thing early. A phone left in another room. Remembering what someone told you in March. Sleep you didn't negotiate with. Leaving before you're the last one there.

All of it is cheap in money and expensive in the currency nobody budgets: how many decisions you have left when it matters.

Which is why "just be more disciplined" is useless advice at that hour. There is nothing left to be disciplined with. The fix isn't character. It's spending fewer decisions before six.

What to do with it

everything on this list is cheap in money and expensive in the one currency nobody budgets: how many decisions you have left when it matters.

which is why "just have more discipline" is such useless advice at that hour. there's nothing left to be disciplined with.

comment ENERGY and i'll send you the energy rebuild — where the day actually leaks, and the three places to plug it first. free.

The bigger picture

he can move seven figures in an afternoon and can't leave a dinner before midnight. leaving requires a decision, and he spent them all by four.

the most expensive things i know are free.
Put this into practice.

Start with one free protocol — evidence-based and specific.

Get the free protocols →

Frequently asked questions

What is the main idea of "The Most Expensive Things Are Free"?

Being on time. Saying the hard thing early. Six things that cost nothing in money and everything in the currency nobody budgets — how many decisions you have left when it matters.

he can move seven figures in an afternoon and can't leave a dinner before midnight. leaving requires a decision, and he spent them all by four?

the most expensive things i know are free.

How do you actually apply this?

Start with the free protocols at marsa.ai/start — free, and it turns this piece into a concrete first step.

Is this about willpower or systems?

Systems. Willpower is finite and unreliable; the durable lever is changing the system, the environment, and the defaults underneath the behavior.

Who is this for?

Founders, operators, and anyone trying to perform and live well in the AI age — the science applies whether it moves a person, a market, or a machine.

Where can I go deeper?

Start with the free protocols at marsa.ai. Every claim here draws on the clinical literature — see the full bibliography at marsa.ai/research.

About the author

Seçil Sayhan is the founder of MARSA. She spent a decade on one question: what makes a person thrive, instead of just keeping going. Her research tested the obvious answers — nutrition, supplements, physical health — and none of them predicted it; what predicted it was how someone read their own life. Then she built a company of her own and met the same problem from the inside, which is why MARSA has two halves: machines that take the work which repeats, and the training for the person those hours come back to. BA Business Management · MSc Clinical Health Psychology and Wellbeing · Diploma in Neuroplasticity · Lifestyle Medicine, Harvard University. Every method traces to a public bibliography of 190+ peer-reviewed sources: see the research.