People do not go wrong from lack of intelligence; everyone goes wrong at the same points. The recurring patterns.
Continuing because of what you have already put in is the sunk cost fallacy. That money is gone whichever option you take, so the comparison should only be about gains from here. Sitting through a film you dislike and holding a losing investment share the same structure. Asking 'if I were deciding fresh today, would I choose this?' usually settles it.
Once you settle on a conclusion, information supporting it becomes unusually visible, while contrary evidence gets picked apart. The practical defence is searching for the counter-case yourself first. Writing down in advance what you would expect to see if you were wrong makes it firmer still.
Not changing feels safe, but keeping things as they are is itself a decision with its own cost. Not cancelling an unused subscription, or leaving a product whose terms have worsened, both belong here. Asking whether you would sign up today if you were not already using it makes the call easier.
In negotiation or shopping, the first figure presented becomes the reference point for everything after. It is why showing an original price makes a discount effective. Deciding what you consider reasonable before seeing any number reduces the pull.
Memory rewrites itself once you know the outcome. Good decisions get remembered as good judgement, bad ones as unavoidable. Two or three lines written at the moment of deciding let you check later what you actually misread. Judgement grows from records, not from experience alone.
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