..."God Incarnate wasn't aware of the origin of human sin and misery?"...
Catholics believe two things about Jesus – that he was Divine ; but also that he was fully human.

 It is often difficult for us to comprehend how these two things work together. But as a fully human person, Jesus chose to limit his human knowledge to whatever was the knowledge people had at his time and at his place.

  He took the 'bible knowledge' as taught in his time, by the bible scholars of his time. He understood the physical world as people of his time understood it.

  As a Jewish person of his tie, he would not have 'known' of the Universe as revealed by Hubble telescope, or of the planet earth, or continents like the Americas or Australia or the Polar regions.

His choosing to becoming 'fully human' does come with all its human limitations.