Why do I have to keep changing positions? Despite riding seriously -- about 6,000 miles/yr -- for over 20 years, I apparently have some kind of obsessive-compulsion thing about always fooling with my bike fit.  (95 changes -- NOT a typo! -- last year alone.)  Seems to get worse every year.  Before resigning myself to this being a "mental" thing, anyone know if it's possible there may be a physical reason for this?  For instance, I use the "hands-off" test to determine the seat's fore/aft; I find it very hard to believe that some "mental condition" could result in me being able to pass the test with a 6 cm -- tip behind BB -- setback one day, then a few days later, I can't pass it unless the seat is 9 cm back!!!  And, yes, I've had several bike fittings.  (It's soon after those that I REALLY went nuts changing things due to the resulting loss in efficiency and/or pain.)  The fitters seem to be confused, too!  The range of their fits includes:

seat height (BB-seat): 81-82 cm

seat setback (BB-tip): 5.5-9 cm

bar reach (tip-bar): 53-56 cm

bar drop: 5-8 cm

After changing positions, it feels much better for a few rides.  Then, on one ride, the fit suddenly feels so screwed up, its as if I'm on someone else's bike!  I then recheck things, discover something has to be changed by a centimeter or 3.  Then it feels WAY better -- and is usually WAY faster -- until a few days later, when something is obviously wrong . . . and so on, and so on.

So, any ideas as to why -- besides the mental thing?  Anything to try? If it helps, I'm 6'2" with an inseam of about 36".  My torso is pretty short, relative to my legs, and I think my thighs are on the short side relative to my lower legs. (Guess I could average out all the fittings, and see how that works.)  I realize I may need a sports psychologist more than a bike fit expert, but I don't have the time or money for that!
Fit is a dynamic thing, but it's not so dynamic that it needs to be changed as often as you're changing it. I'm no psychologist, but I think it's safe to say it's a mental thing. Making adjustments feels better and faster because it feels new for a few rides and then you get used to it. Split the difference of all the measurements you listed and leave it that way for awhile. Be honest with yourself when you feel the need to make an adjustment and realize that once you're within the range of fit that works for your body, no small change is going to make a night and day difference.
If you've been making that many changes for years, you've basically conditioned your mind to react the way that it does and you'll never be happy because of it unless you just leave the fit of your bike alone, unless of course it truly needs to be adjusted. The challenge for you will be determining the difference.
This is not all that uncommon of a condition. I've seen people who do it with bike fit, bikes/components, diet, etc, always expecting the next change to be the one that makes the difference. Just remember that most of it comes down to the rider, especially his/her fitness and skill level, and those things only come with time.