I can recall Hugh Everett's thesis, and how I spent most of a night with him, going over [it], trying to word it in a concrete way. But the ideas in the thesis were so strange to many people that they provoked strange names. And particularly, produced a strange name, the Many Worlds interpretation of quantum mechanics. A certain probability that such-and-such happens and will be in a universe where we see that happening. Or there's certain probability that something else happens and we'll be in a universe where we see that happening. Well, isn't that obvious, you could say. Well, in Everett's mathematical formulation, these possibilities were coexisting and could come together and be extinguished. It was only when what got to the point where one had an irreversible act of observation that one of these became materialized. If there's anything designed to confuse somebody about what quantum mechanics is all about, this does it.