The brain has a happiness set point it returns to regardless of what happens. Lottery winners drift back to baseline within a year. Newly paralyzed people drift back within a year. Promotions: weeks. Every new circumstance gets absorbed and the felt sense of life resets to roughly where it was before.
Santos calls the consequence the satisfaction treadmill: you work harder, get the thing, feel better briefly, return to baseline, need a next thing. Speed increases. Distance to happiness stays exactly the same.
The mechanism is not malfunction — it is what the brain is for. Sustained dissatisfaction kept ancestors hunting, gathering, moving, mating. Permanently satisfied organisms don’t reproduce.
Sermon edge: This is the empirical version of the CSG Book 4 Ch 11 claim that money, power, and knowledge cannot substitute for relational happiness. Decades of psychological research now make the same claim from the bottom up. The pulpit can name what the data already says: the things people most expect to satisfy them are exactly the things adaptation neutralizes fastest.
What does not fully adapt: strong relationships, gratitude practice, acts of kindness, presence, savoring. These are the inputs the brain was designed to keep responding to. See gratitude as the most basic element of faith.