The experience of a moment in the past is bound to that moment in time. The perception cannot be changed, nor the impact of the experience on your mind. Even if new information changes the context or shows your perception to have been false, or others experience of that moment, which in itself formed your experience of that moment and self perception, that contrast with yours are revealed, it does not change your experience. Simply put, say you had a happy experience. You believed others were happy too. Now it is revealed that they were just pretending to be happy. This does not change the fact that you experienced happiness in that moment in the past. You can't retroactively change your perception either.