You studied the menu. You weighed the options. You made a decision you were genuinely happy with. Then the plates arrived and the person across the table got something that looked, unmistakably, more interesting than yours.
This happens with remarkable consistency. The dish you ordered is fine - it is what you wanted five minutes ago - but something about seeing the alternative has shifted the calculation. You are now eating your food with a small, persistent awareness that you might have made a mistake.
There is a name for the underlying mechanism. Psychologists call it "the grass is greener effect" in everyday language, and in more formal settings they talk about "relative preference reversals" - the phenomenon whereby our evaluation of an option changes depending on what we compare it to. When you ordered, you were comparing the pasta to the fish. Once the fish arrived at the neighbouring plate, you were comparing the pasta to a vividly present, visually appealing, slightly mysterious object that someone else gets to eat.
The comparison is also skewed in a specific way. You know exactly what is wrong with your dish. You have eaten it. You know the bit that is slightly too salty and the texture that is a little softer than you hoped. Your companion's food retains all its potential. You have not encountered its flaws yet. The imagination fills the gaps generously.
There is also something happening with loss aversion - the well-documented tendency for losses to feel larger than equivalent gains. Having chosen option A, you experience option B not just as "something you do not have" but as "something you gave up". The act of choosing forecloses the alternatives, and for some people that foreclosure feels like a small bereavement every time the other plate arrives looking better than expected.
The solution, in theory, is straightforward: order from someone else's plate, eat half each, accept that perfect information is not available at the point of ordering. Most people know this and do not reliably do it. The problem recurs at every restaurant, every time, with every menu. It is not a failure of knowledge. It is a feature of how comparison works in a mind that is always, slightly, somewhere else.
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