Are you absolutely sure that's a true statement? Of course you aren't, because it's not. Truth and Reality simply are. Whether any individual person knows a particular truth doesn't make it untrue; it just makes it unknown, to that person. It isn't necessary for everyone else to know something that I know for me to know it.

As Donald Rumsfeld famously alluded, there are known knowns, known unknowns, and unknown unknowns. (He left out unknown knowns.) But don't think for a moment that they aren't absolutely true, even when they're unknown.