Hi Odyinid,
No, you're not going crazy!

The power brakes on the car are vacuum operated. The system takes vacuum off the intake manifold when the engine is running. The engine itself is computer controlled. The computer controls many things including idle speed. It compensates for various loads on the engine, like when the AC cycles. The minute changes made in the throttle to control this, also make minute changes in the vacuue level in the engine and you feel that as a slight shift in the position of the brake pedal. It is perfectly normal and I can't remember owning a car that didn't do this at one time or another. You can duplicate this effect on purpose if you want to. Next time you take the Ody on an errand, try this when you return to the house. Pull in the driveway and let it sit for a few seconds with the transmission in drive. Then simply put the transmission in neutral and pay close attention to what the brake pedal does. If it's like mine, it should settle that short distance you've noticed. That's because you just took the load of the transmission itself off the engine and the computer compensated with the throttle to keep the idle constant.
Now, if the brake pedal ever moves significantly more than that 1/4 to 3/8 of an inch, have the brakes checked ASAP! Other than that, I wouldn't worry about it.
Take Care & Drive Safe,
Steve