I know that likening Black Holes to the Big Bang is common among laymen and that scientifically educated people quickly reply that they are completely different things. But I would like to understand better in which aspects are they similar and in which they are different. If we run the universe backwards, we get to a point beyond the CMB where matter ceases to exist as such, it all gets so hot that even the quark-gluon plasma and the radiation fuses into some sort of "primeval energy" where particles are not yet formed, and the different forces get unified, possibly also gravity just a tiny instant after the BB. Let's forget the singularity itself, but at that tiny instant after the BB, all forces are possibly unified, spacetime is tiny, and all the energy is confined in that spacetime volume with an inconceivably high density. In a Black Hole, the matter-radiation falling into it also gets increasingly condensed into an ever smaller volume. Again, let's forget about the singularity itself, let's just go a point very close to reaching the singularity status. The energy density gets also incredibly huge. But, do other analogies hold? The confinement of all the mass-energy in such as small volume, does it mean that the center of the black hole must be a very hot place? May the matter-energy become a "quark-gluon plasma plus radiation" near the center, and just "primeval energy" even closer to the very center? Can we assume that the different forces also get unified as we get closer to the center of the black hole? We surely feel the gravity of the black hole. Perhaps that would mean that gravity does not actually unify with the other forces even at near-singularity conditions? Could we say that "time runs backwards" beyond the event horizon and towards the hypothetical singularity? In summary, here I have proposed some questions, but in general I'm interested in getting to know better in which respects are Black Holes and Big Bangs similar or different, seen as possibly reverse manifestations of a same concept, i.e. energy emerging from (hypothetically) infinite density into a growing spacetime as time moves forward, vs energy compressing into (hypothetically) infinite density into a shrinking spacetime as time moves (in principle) forward.