I would imagine that the vast majority of students at Universities around the world who take Linear Algebra "master" it in 10 days. That is, the ten days before

I would imagine that the vast majority of students at Universities around the world who take Linear Algebra "master" it in 10 days. That is, the ten days before the exam, having spent most of the term drinking, socialising, falling asleep in lectures (or just staying in bed and skipping the lecture bit). I certainly know I "mastered" elementary linear algebra in about 10 days.