Have you comprehended the breadth of the earth?
Tell me, if you know all:
Which is the way to the dwelling place of light,
and where is the abode of darkness,
That you may take them to their boundaries
and set them on their homeward paths?
I know, I know, I know.. I remember a conversation with my dad when he stopped talking and said those words. I replied, "Huh?" He told me that was the number of times I had absentmindedly spoken words in the course of listening to him give me advice. I had asked his opinion and (he was long winded to be sure) but as he was answering me, basically he heard me telling him that I already knew it all. We chuckled because he knew I was simply saying those words much like someone would say, "Uh huh" or "Yes, yes" really to let him know I was still listening, but the words I chose were "I know" to which he replied, "If you already know, why ask?" "I don't know" was my reply.
God knows we don't know it all either, and sometimes it is good for us to hear that. It should be comforting to know that God is in control, that He spins the earth's orbit and tells the seas where to stop at their shores. We want to control our lives as far as what will happen, and when, and who will be there for us. We want to know how many days we will have, and how many friends, but is the answer to those questions going to change the way we make decisions? If we knew the number of years we will live, will that change a decision we make right now? I think it's more important to let God determine those answers while we live right now in the moment, making decisions by praying to God for guidance and inspiration and letting God be God today, and then we can rest, knowing He is always present for us, attentively listening for our prayers.