Moses, it is written, was the most humble of all men.
Obviously, he knew who he was. He knew that of all men, he alone was chosen to accomplish the greatest tasks of history—to lead an entire nation out from bondage and bring them to the greatest revelation that would ever be. He was the loftiest of all prophets, who spoke directly to G‑d whenever he wished.
He knew all this and yet he was humble.
Because Moses told himself, “This is not my own achievement. This is what I have done with the powers G‑d has gifted me. Perhaps, had someone else been given these same powers, perhaps that someone else would have done an even better job.”