Oh, most definetly steal EVERYTHING. When writing books: who needs original ideas? The ideas other people have come up with are already perfect, so why bother? When doing groceries: the grocery store doesn't need that gallon of milk, you do, so just steal it, they won't mind I'm sure. How about your grandma's fake hip? She didn't need it before in her life, so I'm sure she'll be sure without it.