There were so many quotes like that in the movie, but I missed this one. I noted that Laurie says "I'm crossing all kinds of boundaries". And Lee says about Mike "he's not the man I married". There were tons more but I didn't write them down. That's what I loved about it. You rewatch it and see an almost completely different movie. Yep. I don't see how you can explain it without the science, it's woven into the plot and it is the basis for everything that happens. Hell, Hugh is probably named after Hugh Everett, the guy who came up with the many worlds theory. I kind of thought the same thing, but Mike said at one point "this only started tonight, if there are a million realities I banged your wife in all of them". I think it means people don't stray that far from who they really are. And anyway, what's available in THIS BOX would only be the branches created by decisions made during the comet. Or something.