[bennyelv]

Fair enough - and I agree with your argument. But it begs the question, if you know that the better life was within your grasp with expectation P then why did you not make the opposite decision?

Maybe you know things now that you didn't know when you made the decision. Or the circumstances which you hoped wouldn't come true as a result of your decision did come true so you got the lower probability sub-optimal outcome rather than a better one. Or maybe future you is different to past you and has different priorities which you didn't predict.

Either way, you can only make decisions on the information you have and with the judgement mechanisms you have learnt at that time.

With that in mind, regretting a well thought out decision that you now think was sub-optimal still seems odd to me!