His goal is artificial general intelligence, something that seemed to grab his attention after he was already actively working on VR. My guess is that when he s

His goal is artificial general intelligence, something that seemed to grab his attention after he was already actively working on VR. My guess is that when he started teaching himself machine learning, he realized that he needed to focus all his attention on it if he was going to take it seriously. Facebook's failings just accelerated this for him.