When I studied group theory, I would have been so much happier if someone told me we were talking about nonzero numbers, or invertible matrices, or functions.

When I studied group theory, I would have been so much happier if someone told me we were talking about nonzero numbers, or invertible matrices, or functions. A little of bit of concreteness would have helped enormously to motivate the topic. When I took real analysis, I would have been so much happier if the teacher had presented some historical context: what pitfalls had mathematicians fallen into by misunderstanding infinity? That’s just how my brains work. I need some context. I suspect other brains are like mine too.