My acceptance speech at the Turing award ceremony: Good evening ladies and gentlemen. The main idea of reinforcement learning is that a machine might discover what to do on its own, without being told, from its own experience, by trial and error. As far as I know, the first person to propose this was Alan Turing in 1947, which makes it particularly gratifying and humbling to receive this award in his name for reviving this essential but still nascent idea. I have three people that I would like to particularly thank. First, Andy Barto. As my PhD supervisor he taught me my whole approach to science, and in particular instilled in me an appreciation of scholarship and craft, and of the great breath of prior work. Second, I would like to thank Oliver Selfridge, my other main mentor; sadly, now deceased. Oliver taught me how keeping ideas simple can be the boldest of all ambitions. Third, I want to thank Martha Steenstrup, my life partner and intellectual sparring partner. She keeps me honest and grounded. Finally, I also want to thank the University of Alberta, which has been an ideal environment for me and for reinforcement learning research these past 22 years. These three people and my university have reinforced in me the ambition to have ideas that matter, without getting too full of myself about it. They taught me that the quest for better ideas is serious, but is best approached playfully, with humility, kindness, and optimism. For this I am eternally grateful. I would also like to thank all of you for being here and for celebrating the pursuit of intellectual excellence. Thank you very much.