Walking to campus this morning, a light bulb appeared above my head... The concepts that I've mastered, I define mastery as an intuitive understanding of problem solving methods, have one thing in common. I've practiced or used these ideas repeatedly, so they are stored in my long-term memory. For example, I self-studied propositional and predicate logic through UC Davis Logic Primer, which has a ton of problems and exercises with solutions. I've also had to use logic in: Discrete Structures, Analysis, and arguments with my wife. I'm wondering if you guys know about any books with lots and lots of problems with solutions for these subjects: Statistics, Probability, & Advanced Calculus (as per the topics covered in Baby Rudin)? Note: I have a copy of The Probability Tutoring Book, which does have a lot of problems with solutions, so a good probability book is the lowest priority of the above 3 subjects.