You just have more latitude than some of us. I can't explain it. My range is more like 6 millimeters. Beyond the front of that, my hands start to hurt. That also is the point where my spin falls apart and my knees start to hurt. Behind that, I can't control the bike as well, my spin loses torque, and it's too much of a grunt to get out of the saddle.

You know, even a certified fitter will allow some latitude for comfort and control.