There has for many years been a debate as to why anything exist at all when during the Big Bang matters twin,'anti-matter' ought to have completely anihilated 'matter' completely.
I think that is absolutely WRONG,in that infinitely small duration of time, 'matter' did NOT exist,all that existed was ENERGY,for however brief an amount of time & because no matter existed neither did GRAVITY.
From that energy, E-MC2 began the process of forming matter beginning with Quark Gluons & onto formation of atoms in humongous quantities,so vast - dense,superhot, that in 300,000 years, a thermal cloud the size of the size of the Andromeda Galaxy had formed.
The thermal heat generated could only attempt to escape through inflationary expansion, that continues today.
As long as there are two-bodies under gravitational influence of each other,there will be heat & the prospects of every bit of matter reaching thermal equilibrium with it's background will take a very long time to be reached.
Even some 13.8 BILLION years after the Big Bang, the very atoms formed then(including the billions in each of us)are still around today & will be for evermore.
That is truly amazing,with no 'tooth fairy' in sight either.