Is it worth reflecting that perhaps the big bang singularity is itself far from well understood?
Big Bang cosmology plays the 'video tape' of expansion of the universe backwards so we find all the matter, space and time of our observeable universe compressed into a 'singularity' of infinite density and heat at time=zero seconds.
Fair enough, but the singularity itself is not directly observeable (I've put up a prior modest post about the phenomenon of nature constructing event horizons around singularities, with a link to an interesting web page at the University of Oregon,
here) and our best theories, relativity and quantum mechanics, are incompatible at t=10^-43. Science does seem to have a good handle on events after that, but even then relies on inflation which is less well understood than the rest of the standard cosmology.
We don't
really know
where the universe came from...
just my $0.02
