> Erm. I disagree. Isn't there a possibility that people might be harder on themselves than their boss might, maybe even subconciously to beat the boss to the punch?

Being too hard on yourself is still not being objective about yourself -- it's just subjective on the other end of the spectrum. It's really hard to evaluate oneself accurately. Some philosophers posit that it cannot be done. I don't go that far, but I do think it's a tough job and requires one to have a very analytical mind and an unusual balance between pride and humility.