And then he goes to explain that in clojurescript, you have access to the google closure library . So most of the stackoverflow questions that he goes through are trivial in clojurescript.
This one about for-in deserves a special mention because of the length required to go through all the details. And the gist of it being: “Don’t use it, it will hurt you”
 Why isn’t that library isn’t more popular? This is what google uses for most of their apps including search, maps, gmail, docs… not angular