If there's one thing the Lord had taught me that made me just look back and become grateful that He called me- is the understanding that we are living in world where you can be trapped of the illusions of a great life and then spend your whole life running after it then realize that it can never satisfy you at all.
Life here on earth is short. And eternity never ends. How come I almost spent my entire life working on my life here and never even bother to think of how will I be spending eternity?
And I am grateful that God called me. And now He is teaching me everyday of how should I live my life here on earth in order to get the great reward I will be enjoying in the eternal life.