Because the journey to arrive at the truth is just as important as the truth itself. Also, to arrive at the complete truth u need the middle to traverse to either end. Hence, the importance.
"truth lies'...Nice pun. Truth occurring at both ends is an illogical premise. Imagine a meter stick, where one end is 100cm and the other is 0cm. If truth is 100, is 0 also truth? Somewhere there must be lies.