The saddest thing was actually getting fed up with one another. It's like growing up in a family. When you get to a certain age, you want to go off and get your own girl and your own car, split up a bit.
Changes. . . can only be effected by alterations in the original. The only thing not prerecorded in a prerecorded universe are the prerecordings themselves. The copies can only repeat themselves word for word. A virus is a copy. You can pretty it up, cut it up, scramble it - it will reassemble in the same form.