Monopoly is a great game, carefully designed to awaken the natural capitalism that lives in everyone's heart. However, the most interesting thing about the game is the money.
When you're playing the game, money is what it's all about. But, the moment the game stops, the value of the money vanishes - as dew, evaporating in the dawn's light.
As a metaphor for the futility of attaching numeric values to achievements, I can't imagine anything more perfect than Monopoly money. While you're playing the game, nothing else matters, but once you win or lose, it becomes irrelevant.
A lot of things in life are like this - not least, the grades you get in school. Granted, these grades do have some small effect on your options - but in the long run, it is your individual properties and capabilities that determine your success, not an abstract figure on a piece of paper.
Remember that, the next time you feel tempted to obsess about an artificial value judgement - or about anything that has no real intrinsic value...