Seneca wrote something that financial professionals almost never apply to themselves: that most people confuse the value of a thing with the effort they've spent acquiring it. He called this a kind of self-deception — not greed, but a subtler error, where the labor of reaching a conclusion makes that conclusion feel more certain than it is. The philosopher who spent thirty years understanding markets, like the collector who spent thirty years acquiring rare objects, begins to price his own opinions at the cost of the work, not the quality of the argument. This is where Amos Tversky's research on 'sunk-cost entrapment' and Seneca's moral psychology meet: both are pointing at the same mechanism — the past investment colonizes the present judgment, making an expensive idea feel like a valuable one. The practical implication is uncomfortable. The longer and harder you worked to form a view, the more suspicious you should become of how much you trust it — not because effort is worthless, but because effort and accuracy are orthogonal. The question isn't how long you've held a position. It's whether you'd reach the same conclusion if you were starting cold today.

Name a financial or professional position you've held for more than a year — if you encountered the same evidence today for the first time, would you take the same position?

Drawing from Roman Stoic Philosophy / Behavioral Economics — Lucius Annaeus Seneca (Letters to Lucilius) and Amos Tversky