Toby, What Prompted the Shift in Focus?

Ten years ago, you were more focused on reducing poverty and disease. And now your focus is on improving the long term future of humanity. I'm curious about what prompted that shift and focus for you. Was there a particular argument in the last ten years that changed your focus or can you not pinpoint at that precisely? The biggest change was when i came to oxford, and nick bostrum had just got to oxford as well.