Married life is very frustrating. In the first year of marriage, the man speaks and the woman listens. In the second year, the woman speaks and the manlistens. In the third year, they both speak and the neighbors listen. That happens in most countries, son.
Files disappear, only to reappear mysteriously a year later, in another directory.
You know it's guilty of trashing your system, but you just can't prove it. Nothing works, but all your diagnostic ware says everything is fine. Probably harmless, but it makes a lot of people really mad just thinking about it. Takes a couple bytes out of your Apple. Your computer gets fat, slow, and lazy, then self destructs, only to resurface at shopping malls and service stations across rural America.