I think it’s amazing that you can design algorithms that might have society-level impact. AI algorithms are in that category. And, AI is fun . Take Genetic Programming, where you write computer programs to evolve other computer programs. Moreover, AI poses exciting engineering challenges like scaling, and it asks the biggest questions, like the nature of the mind. For these reasons, AI was my first love. I started my AI reading and hacking intently in the early 90s. By 1997, I was far enough along hacking AI that people started paying me to do it. I never looked back, doing two companies and a PhD on AI.