Our idea of the birth of the Universe through the Big Bang is only our limited idea about the Universe and not a real explanation of the Universe itself as it may be and not as we think it is. Therefore, we would have to define, in the first place, what a real Universe is. We have to determine whether we can always use our ideas about the Universe as a basis for understanding the Universe. But, if we are not sure we understand, or know with certainty, or at least to a high degree, what a real Universe is, in its totality, known and unknown to us, then we must think about it more hypothetically.