It is July, Athens is a kiln, and I have spent the heatwave indoors doing the thing I loved most at nine years old: building.

It started as one small idea and became, the way these things do when you are enjoying yourself, a whole small city. I have been making rooms on the internet, under my own name, each one a little world. A room for my music. A room for the books, where anyone can read them. A room that turns a person's answers into coordinates in space, because I wanted to see friendship as geometry. A synthesizer that lives in a browser, neon and ridiculous, because the world needs more instruments lying around where anyone can press the keys. Even a hidden room that shows, step by step, how a machine turns a sentence into meaning, built mostly to explain it to myself.

Some of it is useful, some of it is pure toy, and the distinction, I have decided, is none of my business anymore.

Because here is what I noticed somewhere in week two, soldering interfaces together at midnight with sweat on my forearms and a stupid grin on my face: I know this feeling. This is the exact feeling of being nine, on the floor, surrounded by the parts of something I had promised to reassemble before anyone noticed. The pull that made me take apart radios and build them back, that made me learn to code before I knew it was a career, that made me spend three years studying a computer I did not yet own. The physicists have a word I keep coming back to, conservation: energy is never created or destroyed, only transformed. It is true of joy too, I can now report. The building joy of a nine year old does not expire. It waits, conserved, through whole decades if it must, for conditions that allow the transformation again.

And I know what the enabling condition was, because this whole notebook is the story of it. Curiosity needs slack. The kid on the floor with the radio parts had no deadline, no audience, no metric, nobody asking whether disassembled radios scale. For years, my building energy was all spent through channels that kept score, and things that keep score are careful, and careful is the enemy of the particular joy where you try the weird thing just to see what happens. The quiet mornings, the walks, all this patient subtraction I keep documenting, what it actually purchased, it turns out, was slack. Room for the old current to move again. First it rebuilt the mornings. Now, apparently, it builds rooms.

My favorite part of the month: a friend asked me, reasonably, who the little city is for. Who is the audience, what is the plan. And I heard myself answer with the truest sentence of the summer. It is for whoever wanders in, I said, but honestly, it is for the kid with the radio. He had a lot of unbuilt things queued up.

We are working through the backlog.

There are more rooms coming, because stopping does not occur to me and no longer needs to. The heat breaks in September. The grin, I suspect, does not.

Build something useless this month, that is the field instruction from July. Something with no metric and no audience, out of whatever your radio parts are. Notice the grin arrive on schedule, decades conserved, not one volt lost.

The physics guarantees delivery. It always did.