The Deranged Mathematician: An Introduction to Differential Geometry
How do you summarize a field like differential geometry? A year or so ago, I was asked to do just that. My first thought was that this is just straight-up impossible to do in any reasonable way. Upon reflection, I softened that view. I still think that differential geometry is just not something you can learn quickly, but if you just want the eagle-eye view of the basic constructions and how they are used in different branches of the field... that is doable. Hence, this article.
Differential geometry is such a deep topic—your point about it not being quick to learn resonates. What key concepts would you highlight in that summary?