John, here's my experience with the course.

1. Filling in the details is the greatest feature of this course actually, which comes with a price - much more time is needed because of numerous rabbit holes encountered by the way. The touch on logic was really fascinating, many things clicked for me at once. Another cool example is the tropical algebra, which we encountered during Chapter 2.

2. The concept of adjoints didn't click for me until I started my own investigation and discovered that functors, natural transformations and adjoints have weak analogies in topology, namely with continuous maps, homotopies and (weak) homotopy equivalences respectively. After refreshing my scarce knowledge in topology (probably a lecture during undergraduate calculus a decade ago), using Hatcher's Chapter 0, it became clear that all physical/visual intuitions humans have concerning shapes, their deformations and retractions into each other, were usurped by the modern definition of topology, which deals with undirected, abstract continuous spaces.

So, as I see it at the moment, it is no wonder that Mac Lane and Eilenberg have to come up with a more general concept, which allowed to work with directed, discrete spaces, while conceptualizing the same natural notions of continuity, shape and deformation, and called it category theory.

So in my view it is the biggest omission of the book and the course not to mention such correspondences in the Chapter 1, because they naturally appeal to human physical intuitions. It is clear that most (all?) of mathematicians use some sort of "visualizations" for concepts they use, but since they try to avoid to be imprecise and too wordy in their papers, such intuitions are rarely appear there. But in an introductory book and a course one has such a freedom :)

3. Also, it seems to be a mistake not to provide more time for Chapter 3, or make a pause for at least a few weeks after it (the concept is called spaced learning). This is the cornerstone chapter - either you understand it, and everything collapses at once, or there is no reason to actually proceed. And even if you got this "closure", you need some time for everything to settle down, and proceed refreshed.

So I slowed my pace, filled some gaps, looked on things from different angles, and almost completed it, just need to reread 3.4 + limits with a gained perspective.

My advice is not to give up John, but in order not to burn yourself down, postpone new lectures until the October/November. Also don't give up on your style and the style of the book - what we are actually learning is not just category theory, but the skills of generalization, engineering of arbitrary theories and algebras - on a number of nice mathematical and applied examples.

And thank you for everything you are doing, that's really cool!

1. Filling in the details is the greatest feature of this course actually, which comes with a price - much more time is needed because of numerous rabbit holes encountered by the way. The touch on logic was really fascinating, many things clicked for me at once. Another cool example is the tropical algebra, which we encountered during Chapter 2.

2. The concept of adjoints didn't click for me until I started my own investigation and discovered that functors, natural transformations and adjoints have weak analogies in topology, namely with continuous maps, homotopies and (weak) homotopy equivalences respectively. After refreshing my scarce knowledge in topology (probably a lecture during undergraduate calculus a decade ago), using Hatcher's Chapter 0, it became clear that all physical/visual intuitions humans have concerning shapes, their deformations and retractions into each other, were usurped by the modern definition of topology, which deals with undirected, abstract continuous spaces.

So, as I see it at the moment, it is no wonder that Mac Lane and Eilenberg have to come up with a more general concept, which allowed to work with directed, discrete spaces, while conceptualizing the same natural notions of continuity, shape and deformation, and called it category theory.

So in my view it is the biggest omission of the book and the course not to mention such correspondences in the Chapter 1, because they naturally appeal to human physical intuitions. It is clear that most (all?) of mathematicians use some sort of "visualizations" for concepts they use, but since they try to avoid to be imprecise and too wordy in their papers, such intuitions are rarely appear there. But in an introductory book and a course one has such a freedom :)

3. Also, it seems to be a mistake not to provide more time for Chapter 3, or make a pause for at least a few weeks after it (the concept is called spaced learning). This is the cornerstone chapter - either you understand it, and everything collapses at once, or there is no reason to actually proceed. And even if you got this "closure", you need some time for everything to settle down, and proceed refreshed.

So I slowed my pace, filled some gaps, looked on things from different angles, and almost completed it, just need to reread 3.4 + limits with a gained perspective.

My advice is not to give up John, but in order not to burn yourself down, postpone new lectures until the October/November. Also don't give up on your style and the style of the book - what we are actually learning is not just category theory, but the skills of generalization, engineering of arbitrary theories and algebras - on a number of nice mathematical and applied examples.

And thank you for everything you are doing, that's really cool!