My brain HAS been out to lunch of late!

I found a solution (response to people asking about my pain/condition) that my wife & I have both been using for the past year or two, and it just slipped my mind in previous posts....

Friends, etc.: "How are you?"/"How're you doing?"

Me: "Good days & bad." (or something along those lines).

It works as a social convention, and if people are truly interested/concerned, it doesn't slam the door on them.

Doc