Because when I saw the answer Duchovny - I immediately agreed with it, but I couldn't stop the feeling for "Final Frontier", as if I had heard it associated with those words sometime before. The answer was at the back of my head and I could not understand why! To be honest, I expected it to be linked to a Star Trek episode, called "The Truth is out there", but no, after extensive googling, I found the link attached to my previous answer - but I still prefer Duchovny.