This study investigated the "knew it all along" explanation of the hypercorrection effect. The hypercorrection effect refers to the finding that when people are given corrective feedback, errors that are committed with high confidence are easier to correct than low-confidence errors. Experiment 1 showed that people were more likely to claim that they knew it all along when they were given the answers to high-confidence errors as compared with low-confidence errors. Experiments 2 and 3 investigated whether people really did know the correct answers before being told or whether the claim in Experiment 1 was mere hindsight bias. Experiment 2 showed that (a) participants were more likely to choose the correct answer in a 2nd guess multiple-choice test when they had expressed an error with high rather than low confidence and (b) that they were more likely to generate the correct answers to high-confidence as compared with low-confidence errors after being told they were wrong and to try again. Experiment 3 showed that (c) people were more likely to produce the correct answer when given a 2-letter cue to high- rather than low-confidence errors and that (d) when feedback was scaffolded by presenting the target letters 1 by 1, people needed fewer such letter prompts to reach the correct answers when they had committed high- rather than low-confidence errors. These results converge on the conclusion that when people said that they knew it all along, they were right. This knowledge, no doubt, contributes to why they are able to correct those high-confidence errors so easily. (Contains 4 figures and 1 footnote.)