Yeah! There's that whole thing where you understand how a work is structured, you know what part to pay attention to, what part to skim or read later, where you

Yeah! There's that whole thing where you understand how a work is structured, you know what part to pay attention to, what part to skim or read later, where you're required to do your own calculation to fill in something... People complain a lot that books and presentations don't do everything and that mathematics has a bad "user experience". They may have a point, but the complaining alone won't fix it and will leave most people still feeling like frustrated outsiders.