Behold, God is great, and we know him not. This is the final lesson which Elihu seeks to impress on his hearers. God is so great their fully to comprehend him transcends the power of the human understanding.
However much we know of him, there is more that we do not know. His nature is unsearchable; his depths (1 Corinthians 2:10) are inscrutable; try as we may, we can never "find him out" (Job 37:23). Neither can the number of his years be searched out.
Even his duration, being eternal, is beyond us. We cannot realize the thought of pre- and post-eternity.