A trade was good if it was the right bet on what you knew — even if it lost.

MIND · tips · markdown source

Judging a decision by its result is called resulting, and it is how a good process gets unlearned. A won coin flip does not make the call correct, and a lost one does not make it wrong.

The fix is mechanical rather than emotional: write the reasoning down before the outcome exists, then review the reasoning against what was knowable at the time.