I thought of this myself. If this already exists please tell me who proposed it initially.
The theory of relativity states: Everything is relative.
So relatively, something could be true and something could be false. Could be seen as true or false depending on the perspective.
Then think: if everything is relative, then the statement "everything is relative" is also relative, meaning it could be false at some point at some perspective, but how could that be?
Conclusion: There must be at least one objective thing. "Everything is relative" is the only objective statement. If more exact, perhaps I should say "Everything is relative, except for this statement".
I am 14 and this is deep. Not that kind of deep, this kind of deep. Wait, deep is relative and it is not the statement, so it could be shallow seen from someone else because everything humans have set up are basically relative and non-objective.