Where was this guy when I was struggling mightily through calculus and flunking differential equations? Brought back painful memories even reading it.
While it has been helpful to understand a little bit about how this tool helped to develop the equations I use every day, I can honestly say that in my multi-decade career there has not been a single instance where calculus was required to solve any problem I encountered. Now that is probably more of a statement about the problems I have encountered than about its usefulness as a tool.
Lest any students out there rebel against their professors, I am not saying I didn't need to take it. On the contrary, it gave me a much deeper understanding of how God's natural laws work in the universe. And I understand that, while still imperfect, calculus is one of the best tools we have to approximate our own understanding of that universe.