Being certain and being right are different things. Plenty of confident people remember it wrong.

Certainty is a feeling, and it arrives the same way whether you are correct or mistaken. That is the uncomfortable part, because there is no inner signal telling you which one you are having. Confident people misremember dates, scores and conversations all the time, and they do it with total conviction. How sure you feel is not evidence.

When something matters, go looking for the outside check: the message thread, the box score, the other person who was there. Try saying you think where you would normally say you know, and watch how little it costs. Save the full confidence for things you can show.