(Formerly William McGonagall.)

I left university long ago and have forgotten most of what I learnt from classes. Since 2019, I have been trying to re-learn some undergraduate-level mathematics, but my progress is s~l~o~w~~. Self study is hard. Finding a good textbook is hard. Finding a good and decently priced textbook is insanely hard. In case of differential geometry, I cannot even find a single textbook that is really comprehensible to beginners or the inexperienced. Perhaps I am too dumb.