I actually don't think we're using the word differently -- the issue was premised solely for issues where the answer cannot be known after the fact. In that case, our use of "confidence" is the same -- it simply helps you make decisions. Once the value of the decision is limited to the belief in its soundness, and not ultimate "correctness" of the decision (because it cannot be known), rationality is important only if you believe it to be correct way to make decisions.