We did not remember for very long. The Bible says that Cain killed Abel, but we, too, are skilled at dealing death of another kind with snobbish silence or wicked words. Maybe, at its root, sin is the opposite of blessing. Sin is greed, injustice, intolerance. Sin is dishonesty, insensitivity, and a hundred other things that close us off from the life and love of God.
Human beings do it well.
Maybe that is why, in the fullness of time, God just stopped reaching out across the chasm dividing humanity and Divinity. Instead, God built a bridge and crossed over it in the person of Jesus of Nazareth. Jesus is blessing. In Jesus, God entered into human life in a physical, sensual way and human life was received into the life of God. Jesus was the hope and love of God in the flesh.