Linear algebra was one of my favourite series of subjects during my mathematics degrees. It has always been fun. There was only one rocky moment I can recolle

Linear algebra was one of my favourite series of subjects during my mathematics degrees. It has always been fun. There was only one rocky moment I can recollect, in first year after a three lecture proof which the lecturer finished with words along the lines of: "I won't go through this again because you wouldn't understand it the second time either." Quite possibly true, although I understood the steps of the proof the theorem itself wasn't at all obvious. In later years it became so.