Finding a Way to Stand Down

One of the things I love most about living in Tokyo is the mild winter. Extreme cold is rare, and long, soaking rains are uncommon. So when, one Saturday night in February, I suddenly heard the sound of heavy rain striking our terrace, it felt almost like a glitch in the physics engine of the world.

When I looked closer, it was not rain at all. Water was pouring down from the terrace above us—more precisely, from a square structure normally kept closed, the emergency escape hatch. Because it was positioned close to the glass door connecting the room and the terrace, the water ran down the glass like rainfall. Its milky color suggested detergent, and I quickly concluded that it must be wastewater from a washing machine.

I like to think of myself as open and generous in how I interpret human behavior, especially when it can be explained through evolution or social structure. Yet in this moment, my brain failed to build a plausible model. After briefly examining the structure of the escape hatch, it seemed unlikely that simple leakage could produce such a sudden, heavy flow. The only explanation that felt coherent was that someone upstairs had deliberately opened the hatch and drained water through it.

This bad neighbor hypothesis startled me. It felt like a kind of behavior that resisted explanation—neither evolution nor social norms seemed to account for it.

What disturbed me most was not the dirty terrace, but this failure of explanation. Even after we contacted the management company, my unease persisted. Their reply only deepened it.

They explained that no one currently lived upstairs, and that the water came from a routine cleaning of the terrace before a new tenant moved in. According to them, water had leaked around the escape hatch. They promised it would not happen again and offered to clean our terrace.

The explanation did not fully satisfy me.

The amount of water had been too large and too sudden to resemble leakage. If the terrace had been cleaned, the water should have been darker, mixed with dust and debris, since the surface is bare concrete. And the terrace has a gutter that drains directly into the main system; even excess water should have flowed there, not through the narrow rim of the hatch—unless the drain itself had been clogged.

What I noticed was that I wanted an explanation more than a solution. Compensation and cleaning addressed the consequence, but what I craved was a cause that fit what I had observed.

This led me to a broader question: why does explanation matter so much to us?

A biological answer seems plausible. The human brain is metabolically expensive. One of its fundamental tasks is not thinking itself, but reducing uncertainty. Unexplained events demand sustained vigilance and cognitive effort. Building a causal model—even an imperfect one—can reduce that load. Understanding, in this sense, is not only epistemic but economical.

Seen this way, the history of knowledge looks like a long attempt to make the world predictable enough to live in. From early beliefs that forecast rain to modern science that models natural laws, explanations offer relief. When phenomena behave as expected under the same conditions, we relax. The world becomes inhabitable.

I noticed this instinct in myself when, still unconvinced by the explanation, I briefly imagined recreating the conditions upstairs—how much water, what kind of pressure, which angle might reproduce that sudden downpour. The thought passed quickly. Another part of my brain intervened, calculating the social cost of becoming an unreasonable tenant. Curiosity stopped where politeness still mattered.

That impulse—to explain, to test, to reproduce—felt familiar.

Years ago, as an undergraduate, I took a popular sociology course titled Human Behavior and Social Structure. When the professor introduced a controversial topic, many of us protested that we did not want to know. She responded calmly with a line I have carried with me ever since: “If you know, then you understand. And when you understand, you love.”

At the time, the sentence sounded idealistic. Now it feels almost anatomical. Understanding, I realize, is often what allows the body to lower its guard. Babies ask “why” endlessly, a habit we often attribute to the neocortex and celebrate as curiosity. But perhaps this drive is also a strategy—an invention that allows an organism to conserve energy by turning the unknown into something stable.

It is striking that this same impulse, born from the need to manage uncertainty, can lead both to scientific discovery and to social generosity. In trying to understand the world, and each other, we may simply be doing what our brains learned to do best: finding a way to stand down.