I just finished taking “Applied Category Theory” at MIT! No, of course I didn’t get admitted to MIT; I watched it all online for free! The book (not yet published) is available online for free as well! What an amazing resource! Thanks so much to David Spivak and Brendan Fong for their incredible generosity. I guess thanks should also go to the Massachusetts Institute of Technology and to Cambridge University Press for allowing this to happen.
I loved this off-hand remark about the set of all sets that Spivak made in chapter 3, lecture 1, at 36:58.
“If you’re worried about that, it’s because you’ve been trained to be, probably, more than because it’s actually a worry.” – @david_i_spivak