Comment by ajmurmann

It's also that you might have a better idea of events that couldn't have been foreseen at the time. Maybe working hard didn't pay off because you lost much of the savings in a bad investment or a bad divorce anyways. Maybe you could have done with fewer savings because of a larger than expected instance or stock reward. Or maybe the fruits of some efforts never materialized anyways. With the information available at the time the decisions might still have been the correct ones.