Denis Doyle has passed. I didn’t know him really well but was fortunate enough to cross paths from time to time around various things. He was early to the leverage that data provided in education and built, with others, a company around that – Schoolnet. A few things stand out. First, his mind. You run into smart people in this sector all the time, and then you run into *smart* people in this sector. He was the latter. A real intellect, polymath, and curious person. Second, he was funny. He was kind, but he was hilarious. And finally, upon his passing, it was noteworthy the number of people who said things like, “a real mentor to me.” People spend a lot of time worrying about impact and legacy. People calling you out as a mentor, it seems to me, is impact and legacy.