Hello there, This might be an unusual question, but please bear with me. I understand that over time it is imminent for the trackpad to become worn and look "shiny". I also believe the same applies to the keyboard. My question is this: Does the plastic on the trackpad that gets worn by the friction of your fingers leave residue on your fingers? Is this residue harmful to you? And also, the plastic that gets worn...where does it go? On your fingertips or what?