Most people believe that they should avoid changing their answer when taking multiple-choice tests. Virtually all research on this topic, however, has suggested that this strategy is ill-founded: Most answer changes are from incorrect to correct, and people who change their answers usually improve their test scores. Why do people believe in this strategy if the data so strongly refute it? The authors argue that the belief is in part a product of counterfactual thinking. Changing an answer when one should have stuck with one’s original answer leads to more “if only …” self-recriminations than does sticking with one’s first instinct when one should have switched. As a consequence, instances of the former are more memorable than instances of the latter. This differential availability provides individuals with compelling (albeit illusory) personal evidence for the wisdom of always following their 1st instinct, with suboptimal test scores the result.