How small of a fit change is big enough to make a difference?
Here's an example. I decided to tilt my saddle nose up a bit, from slightly nose-down to flat. The change was less than 5 degrees. Within a day of riding (commuting) on the new fit, my knees started to hurt, just twinges, but persistent and repeated twinges. After a couple days of this, I figured that the change had raised the center of the saddle a little bit, so I lowered the seatpost a very small amount, about one-quarter of an inch. My knees are no longer twinging. I'm a little surprised. I know a saddle that is too low causes me knee discomfort immediately, but I didn't think a saddle just a tiny bit too high would do so. I am a little perturbed, actually, I had thought I was more robust than this.
Have you found yourself sensitive to very small changes, in any respect? Examples? Or, do you think it is just psychological, imagination?