"Although I’m only 48, I have been working in educational computing for thirty years. When I started, we taught children to program. We also taught tens of thousands of teachers to teach computer science to learners of all ages. In many cases, this experience represented the most complex thinking about thinking that teachers ever experienced and their students gained benefit from observing teachers learning to think symbolically, solve problems and debug. There was once a time in the not so distant path when educators were on the frontiers of scientific reasoning and technological progress. Curriculum was transformed by computing. School computers were used less often to “do school” and more often to do the impossible."