“The truth is just a lie” is a true statement if it’s true that truth is real only as neurons in a brain, and so existing relativistically per person. This yields universal truth as a lie but truth as a universal human trait plausible (i.e. neither true nor false). Meaning, believing truth to be true is truly something that occurs.
Now, we must notice a lie must be differentiated from a false statement. Untrue statements are inherently a performance of applying falsehood rather than being false truly. To lie is prevarication, deception, or an otherwise intended misattribution. Therefore, it’s not a lie to say something that is not true if you believe it isn’t false.
In the end, the lesson here is one of relativism. Truth’s nature is not in the external world but rather in the internal world of the cognitive agent which mentally manifests truth. Truth is not a lie to the believer, but may be considered a lie to a non-believer, even though technically it is true to someone.
True? Or do you believe it’s true I’m just lying?