This might help others trying to learn this material. I found it easiest to watch a few lectures, but without being overly concern about learning exactly whats going on. This gives you a basis to work from.Then get the text book and work though it slowly. Write down the examples in the book as you encounter them and get used to forming a mental picture for whats going on. The column picture is key.The row picture is probably what your school math teacher taught you. This just confused me a lot. I don't like dot products, but the "combinations of columns" is very intuitive once you can visualize why it works. The reason I found this easier is that the concepts introduced in the videos are a bit loose, its just an overview. The real learning comes from the text book.####[]