First of all, since I'm not the type who can sit still for long periods, I listened to 2–4 lectures during my commute. The lectures are short and concise, and the explanations were easy to understand because you demonstrated everything directly on the screen. I also liked that you covered practical issues I've actually encountered at work, such as "permission denied" errors for executable files. It was great to be able to study with confidence because you explained why certain things must be done a specific way and why others can be skipped. Thank you! :)