In asking this question we implicitly assume that the scale of things always has been the same. But there are no physical or philosophical reasons for why the scale always should be the same. The scale could change with time. The continually changing scale of everything including material objects actually causes what we experience as the progression of time. Since such a scale expansion can continue forever, the universe could be eternal.
All epochs are equivalent.
I will show that an observer living in such a scale expanding cosmos would experience the universe exactly as we see our universe. Scientists who looked deep into the universe at distant galaxies from an Earth in such a scale expanding cosmos would make exactly the same observations that we see in our universe. In fact, I will show that the Scale Expanding Cosmos theory agrees much better with observations than does the Big Bang theory. The Scale Expanding Cosmos theory is of course quite controversial since it suggests that much of what we believe to be true may be false. As you will see, the Scale Expanding Cosmos suggests that there never was a Big Bang creation, that Black Holes do not exist, that there is no Dark Matter consisting of exotic particles, no Inflationary Expansion, and that the Cosmic Microwave Background is not remnant radiation from the Big Bang.