I'm going to side with you here. Loved math as a kid. My high school then used the Chicago series, and I barely got past “Functions, Statistics, and Trigonometr

I'm going to side with you here. Loved math as a kid. My high school then used the Chicago series, and I barely got past “Functions, Statistics, and Trigonometry”. I later got a bachelors and masters in mathematics from pretty good schools, reveling in abstraction and structure. (Said logic compels me to say it's impossible to know whether the Chicago textbook series was responsible for that earlier poor performance, and not the more likely issues of the specific teachers, family, or adolescence. But! Anecdote.)