The AI Hangover
There is a state I end some days in that I did not have two years ago. It arrives after a long session with a coding agent, usually a productive one, and it is not the tiredness a long day of programming used to produce. Food does not touch it, coffee does not touch it, a walk does not touch it. Only sleep.
The obvious explanation is volume, and it fails on its own terms: the exhaustion does not scale with output. Huge sessions leave me fine, and one stubborn module can leave me unable to form sentences.
What changed is the composition of the work. Writing code is mostly production, with decisions as punctuation between long stretches of execution, and those stretches are where you recover. Driving an agent removes the production entirely and leaves only the judgment, continuously, with no gaps.
You did not take on more work. You took on a stream that is nothing but the expensive part.
I wrote the full argument up, including why reviewing costs more than writing and what it means that the recovery gaps were engineered out: