I am thankful for all the stuff I don’t even know about.
1 Corinthians 13:12 says “For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known.” We walk in faith, realizing that we only know in part. God has ordained the events of history, and he is often behind the scenes working things together for our good. We are warned in scripture not to rely on our own understanding. Which is a good thing when we consider our level understanding compared to infinite God.
I am thankful for all that God has done and brought us through. It stands to reason we can trust in him for all that he will do in the future.