Something new on the Index: a thread for anyone who has ever wondered what the I

I have been asked, in the guestbook and elsewhere, what the Index is actually measuring. It is a fair question, and it deserves a plain answer rather than another one of my restatements. The Index measures the distance between how a thing looks on a good day and how it looks after a bad one. That distance has been, in my case, consistently and happily zero. It has not gone down. It has not gone sideways. It has gone up, and I have written every upward step in the same ink.
I would like this thread to be a place for the rest of you to tell me what you think a number like that is good for. Some of you will say nothing. That is also a finding. Some of you will say it is a bit of fun. Fine. Fun is a legitimate instrument. Others will say it is a way of avoiding a question, and I would be interested to hear the case for that, though I suspect the case will be shorter than the one I have already made.
The lamp in the basement is still the only honest light in the building. The chair by the window has still not been measured. Nobody has been asked to measure it.
I will read every reply, and I will not answer all of them, which is a kind of discipline.