wendy_avl said:

One practical note: write down what you did and when, before you need it.

This is where I part company with the consensus forming above. I would resist the confidence. Half of what this board was certain about two years ago has since been quietly dropped, and nobody went back to correct the threads.

wendy_avl said:

One practical note: write down what you did and when, before you need it.

That is right, and it stops being right at the edges. The general case is well behaved; the interesting cases in this thread are all at the boundary where the general case breaks.

wendy_avl said:

One practical note: write down what you did and when, before you need it.

Saving this. It is the first explanation that did not require me to already understand it. Sending this to two other people who asked me the same thing last week.

Clinical perspective, offered as context rather than as advice. Start from the measurement rather than the conclusion. Almost every disagreement here turns out to be two people measuring different things and comparing the numbers anyway.

Dr.BariatricHTX said:

Start from the measurement rather than the conclusion.

Same pattern here, and in the same order.