This one truth …

… First Known When Lost: Arrival.

Wittgenstein's term "the sense of life" (in German, "der Sinn des Lebens") is a lovely way of describing what we may experience during one of those moments when the World communicates with us.  And, although science-enamored, ironic moderns may not like it, "mystical" is an entirely appropriate word to use when contemplating the possibility of arriving at a place where "the sense of life" becomes clear to us.