I didn't word my post very well (I posted the "infinitely old" comment), but what I meant was that it should be more likely to be a Boltzmann Brain in an infini

I didn't word my post very well (I posted the "infinitely old" comment), but what I meant was that it should be more likely to be a Boltzmann Brain in an infinitely old universe than a human standing on Earth in a ~14 Billion year old universe. So why are we the latter rather than the former? That's basically what the anthropic principle is all about. The fact that we are the latter tells us a lot about how the universe, or universes as the case may be, work.