When the Lord commissions Moses to bring the sons of Israel out of Egypt, Moses questions, "Who am I that I should go to Pharaoh?" We learn it's not about, "who am I?" but it's about the One who sends Moses. "I AM WHO I AM" is the God who acts as the Father to His people.
When faced with a difficult task, leaders may ask that question even today, "Who am I?" Does the question come from a sense of fear? excuse and avoidance? false humility? perhaps genuine humility? The motives can be analyzed, but at the end of the day, it's not about "who am I." The servant of the Lord can avoid an ontological crisis by serving the Lord's instruction.