It doesn’t take all that much to create a universe. I found that the only thing you need to get a universe like ours started is a hundred-thousandth of a gram of matter. We can’t rule out the possibility that our own universe was created by someone in another universe who just felt like doing it. Its space would be so curved that it would look as tiny as an elementary particle to its creator.
(Andrei Linde aan het woord in het heerlijke Why Does The World Exist? – An Existential Detective Story van Jim Holt.)