His call in life??
As the movie was "inspired by" the ideas of Ecclesiastes, I find it fitting that the true meaning of the empty life of Qohen is to "find out" that life is empty.. A Big Zero!
{I always felt that Ecclesiastes is a fabricated book inserted into the Tanakh, because the "philosophy" of the text isn't "Godly" at all.. It feels like the writing of a closet Atheist living in old Judea!}
http://en.wikipedia.org/wiki/Ecclesiastes