It's an analogy used to answer to the "But, what's before the Big Bang ?" question. ... so I just answer "What's north of the North Pole ?".

As an analogy for one view of the how the Big Bang might have worked, that's quite a good analogy. It isn't totally fair, though, since that exact question is an active area of research by theoretical physicists, and there has even already been one observational test of a particular version of multiverse cosmology that would imply other universes existing before our Big Bang.