There are also plenty of "nutters" (for want of a better word) out there who can't answer this question in a sensible way. For example I've interviewed people

There are also plenty of "nutters" (for want of a better word) out there who can't answer this question in a sensible way. For example I've interviewed people who claimed to be perfect in a very arrogant and, as you comment, disturbingly un self aware. If you are a decent employee a lot of interview/employment stuff will seem formulaic but I have to say I now use more of this kind of stuff after being burnt a couple of times by taking all this boring sort of stuff as given and then the employee turning out to be unsuitable - in both cases at great cost to myself. In both cases they seemed personable and having the correct skills but the problems where much deeper and would have been turned up by probing and cross checking - which is what this kind of question is actually designed for.