Friend of mine, has a Buick station wagon, 1993.
Last time he did front brakes and rotors, he neglected to take the grease or wax or whatever off the rotors.
We aren't sure, but maybe that was part of why he needed brake pads and rotors again so soon. Does anyone know?
As he was about to put the rotor on, I handed him some spray solvent (carb cleaner; it's what I had). And paper towels, he didn't know about degreasing the rotors. I'd been told to degrease them, by several mechanics I know.
Does it make a big difference? Does leaving the grease on contaminate the pads, and make the pads wear faster?