I learned more about how to think from studying Euclid's Elements than I did from most of my other college classes. The professor was very up-front that it is a

I learned more about how to think from studying Euclid's Elements than I did from most of my other college classes. The professor was very up-front that it is a model for how our notion of the world can be built up from some basic assumptions. It actually made me much better at everything else, more so than explicitly studying higher-level calculus would have. It also helps drive home the idea that what a thing is is not the same as our conceptual model.