Warren talks about, among many things, pleasing God as being one of the purposes in our life.
And just exactly how do we please God? One of the many ways, is through obedience: doing EXACTLY what God says to do, without asking any questions. This makes God smile.
Noah made God smile. Noah was so pleasing to God, that it actually made God smile.
At one point, God looked down on earth and was so disgusted with the human race that He decided to completely wipe it out and start over...until Noah caught God's eye.
What was so special about Noah? Well, firstly, Noah loved God above everything else. Noah also completely trusted and put his faith in God. And then there's that endearing quality Noah had of diligently obeying God.