Truth

What is the truth...what if the truth is a lie and a lies are the truth... would we ever know??
heres a truth : humans have to eat to live. how do we know thats the truth well through experiances of course...some guy some where in history must have died of hunger, thus proving starvation can/will cause death.
but wat about pshyolocial truths that we cant prove. Like how aliens dont exsist...is there any proof?? nahhh...so how do we know thats the truth? we dont...so heres my point no one knows the truth of truths for sure...we're all clueless of the truth...and thats the truth or its a lie...i dont know...i'm lying or am i telling the truth? do you know...yes? thats a lie becuase inorder to find out the truth you must know the lies...but if you only know the lies and are knowlageless of the truth, you end up to be an evil person...said by the world..or society...society is it a lie or the truth?