But... you have to know what a derivative is for in order to be motivated to learn how to do it. If it's all just mindless manipulation, how will one know whether to apply this or that mindless manipulation?
For me it was cause I wanted to beat the shit out of my curve and get scholarship money and letters for grad school. Similar sentiments are found in Hardy’s book I think. If you spend enough time around math professors you will certainly hear a story about so-and-so who is now an acclaimed mathematician who showed up for some undergraduate course when he was 17 or something extremely confused about what the “meaning” of the material was but figured out how to solve all the problems and get an A cause he cared about being good at it (and had the ability to do so).