Proff of an objective truth, Socratic method.

This is building uppon D Galo's question about objective reality.

I chalange someone, (in a friendlly manner of course) to prove to me anything they consider to be objective truth. I ask that you state the concept, idea, or "fact" that you belive to be objectivley true, and just a quick sentence on the most obvious reason why. I will then attempt to play the role of Socrates and simplly ask questions if we get to a point were you have answerd my question and i have no more questions then, well you will have proven an objective truth.

 There is a cutally a really simpleway to get me on this one, hope no one gets it, though im sure you guys will. haha