I just started doing CP-31 as I heard it was a great course, whats bothering me though is that I might not be learning as much as I could from the 800's due to them not being challenging enough. Are the concepts in the 800's building up to something, or can I skip to 1000/1100's (ignore my rating. While taking time doing the problems does not brother me, each solution video is 20m+ and I assuming each tell me the lesson im supposed to be learning from the problem. Should I skip the problems, should I skip the videos unless im confused, any advice would be appreciated.