There was no calculus which, for me, was magical enough. Newton did not study mathematics or science, but natural philosophy. What was natural for him, was unnatural for me, although to be fair I did get a C grade at arithmetic. Using those well know variables of time, speed and motion Newton worked out how the planets moved, how gravity worked and how an apple fell from a tree. This was a ha-ha moment, because, of course, he wasn't sitting...