(This is a parable, with two alternate endings. The reader can pick the ending which suits him.)
Once upon a time there was a man who had the power (whenever he found that he had made a mistake) to turn back the clock, and do the event over again in the light of experience. Now it so befell that this man once took shelter from the rain in a barn, with a very beautiful and seductive young lady.
And, when he told his wife about it afterwards, and she asked him rather suspiciously how he had behaved with the young lady, he replied . . . (http://tinyurl.com/c5avwsr)