1. A lecture that shows how much the author has thought and considered from the student's perspective (seems to consider the learner's understanding flow) 2. Various visual materials and examples make it easy to understand 3. When learning knowledge, it mentions and reminds previous content while connecting knowledge. Knowledge connects and the big picture is drawn. 4. The depth of knowledge is not shallow. I'm taking operating systems right after computer architecture, and the synergy is good. 5. It scratches the itch for "why" & "why is it used" questions. ps. Sorry to the author, but... this is a lecture I want to keep to myself.