experience. You get the 32 pounds of force at the opposite stop pushing the stuff back towards center plus the weight of your leg moving in that direction. Put your leg on the scale and see what it weighs. Once it gets moving, it will go right through the center pretty easily (as compared to breaking it out in the first place) and allow you to get to the opposit stop.
The Sims did not represent that too accurately before. They do now. Its shocking.
If you take your feet off both pedals it will stop at the stop. If you try and go back and forth, you lose the center position pretty quickly. Going from Full left to Full right is much easier in feel than going from neutral and getting the pedal moving.
Cheers
Wino