Hollywood celebrity Terrence Howard infamously thinks that 1×1=2. He's a math crackpot—someone with an irrational amateur theory about math or physics. Another famous example is the Time Cube guy; they're not that rare.

Crackpots don't know they're crackpots. They think they're correct. Consider this: What if we're ALL crackpots? What if all humans share some essential irrationalism, such that there's some fundamental math mistake we all make (like 1×1=2) that we just don't know about?

It's highly unlikely, but it's not inconceivable. When we say "math is objective," we mean there's an overwhelming expert consensus that (e.g.) 1×1 is not and could never be 2. Consensus isn't (true) objectivity, though. It's the best we've got, and I have no issue with the word "objective" being used to describe consensus reality in most cases. But if we really want to get into whether true objectivity is possible or not: how could it be?

As my comment suggests, I believe society is relativistic and there are no objective truths, but I'm open to being convinced otherwise. Of course, I have my own beliefs and principles but I recognize those are a product of where and when I was born and not some objective law of the universe.