Who Am I

At last, I finally voiced it out "Who am I?", I want to shout No, don't tell me my name or my birthdate Nor my favorite drink or the food I usually eat I am asking for my purpose in this world Been living for decades now I feel old I always wonder if I will also shine Like the constellations in the clear sky Or grow like the Poison Ivy vine Or invisible like the air that we take "Who am I?" No one knows, why? Please tell me, for heaven's sake. Before I arrive at the finish line. Can anybody answer this question of mine?