Hi, I ordered a refurbished Black Macbook through Apple, and was wondering if I'm going to have to worry about grease stains. I know that people have said that you have to clean the laptop frequently, but is any of the damage permanent? I know that on a previous laptop, excessive use of the touch pad gave it a permanent "greasy" appearance, and was hoping my new (used) Macbook wouldn't have such a problem. Thanks for the help!