The Experiencing Self and the Remembering Self
Two selves, and only one of them votes. The experiencing self lives through the moments and would answer "does it hurt right now?". The remembering self keeps score afterwards, tells the story, and makes every decision about what to do next time. They do not share interests, because memory runs on peaks and endings and ignores duration. Daniel Kahneman's framing, and one he qualified repeatedly in the same book that made it famous.
What it is
The two selves are a way of naming a gap that measurement had already found. Experienced utility is how good or bad something was while it was happening, moment by moment. Remembered utility is the verdict afterwards. Because the second is built from a few salient moments rather than from an average over time, the experience a person prefers in retrospect is not always the experience they actually had.
The consequence is not a curiosity, it is the whole point: people reliably choose experiences they will have liked less.
Two selves, or two measurements? The distinction matters, and this page keeps them apart. The gap itself is a research finding with a paper behind it, and that paper is the cold-hand study below. The technical vocabulary for it, experienced utility against remembered utility, belongs to a 1997 economics paper by Kahneman, Wakker and Sarin. The two selves, as characters with conflicting interests and only one of them holding the vote, are Kahneman's own popular framing: the shape he gave the argument for his 2010 public talk and for Thinking, Fast and Slow in 2011. That framing is a writer's device, and a very good one, but nothing has ever been measured in its terms. Anyone quoting "the remembering self" is quoting a trade book. The thing to cite is the study.
The framing sits on an old line of argument. Jeremy Bentham defined utility as the balance of pain and pleasure actually felt, and Francis Edgeworth imagined a hedonimeter, an instrument that would read that balance off continuously. The experiencing self is what such an instrument would measure. The remembering self is what surveys measure, and what economics has been measuring instead.