What purpose would such a measure serve?
A crude check of how much you are lying to yourself, for example if you believe that reading LessWrong improved your life. You could enter some data and get the result that no, your life is approximately the same as it was ten years ago. On the other hand, you could also find an improvement that you didn't realize, because of hedonistic treadmill.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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