A simpler maxim is to pay attention to (fixing) cognitive errors at all times, without excuses. Correctness of a prediction is potentially useful data, but it's also an excuse for overlooking flaws in the prediction procedure.

But what are the (potential) flaws in the prediction procedure? The only way to figure that out is to see which cognitive behaviors lead to accuracy, and which lead to error. It is all very well to say that we should not perform cognitive errors, but that does not help us with the problem, because what a cognitive error is, is defined by it leading us away from the truth.