The line is not a productivity tip. It is a market report.

Two curves are moving at once, in opposite directions. The ability to concentrate without interruption is getting scarcer — not because people got weaker, but because the room was rebuilt against it. Open-plan desks. A phone that buzzes for things that could have waited a week. An afternoon shredded into fifteen-minute strips by a calendar nobody defends. Most days you do not lose your focus. It is taken, in pieces, with your consent.

At the same time the second curve climbs. The work that actually moves a company — the argument no one has framed yet, the design that took three uninterrupted hours to see — cannot be assembled in the gaps between messages. When the shallow work turns cheap, and it now has, depth is the part left that neither a machine nor a distracted rival can reach. The two curves crossing is the whole opportunity.

This is why the arbitrage is so large and so ignored. Everyone feels the pull toward the shallows, because the shallows feel like work — the fast reply, the green dot, the inbox brought to zero by lunch. It photographs like productivity. It leaves nothing behind.

So today, before the room takes its cut: ninety minutes, phone in another room, on the one problem that actually needs you to think. Not more of it. Deeper into one piece of it. The scarce thing is not the hours. It is the version of you that can still pay attention.