If you are way beyond all this, you can still pick up new things from Advanced Linear Algebra by Steven Roman[6].
[0] https://www.amazon.com/Linear-Algebra-Stephen-H-Friedberg-eb...
[1] https://www.amazon.com/Modern-Introduction-Linear-Algebra/dp...
[2] https://www.amazon.com/Linear-Algebra-Mathematics-Robert-Mes...
[3] https://www.amazon.com/Linear-Algebra-Introduction-Mathemati...
[4] https://www.amazon.com/Coding-Matrix-Algebra-Applications-Co...
[5] https://www.amazon.com/Algebra-Through-Geometry-Undergraduat...
[6] https://www.amazon.com/Advanced-Linear-Algebra-Graduate-Math...
I'm not sure that linear algebra is an elementary topic, if the word "elementary" is as in math of elementary school. That said, I don't think there's much confusion about linear algebra either. It's more likely that linear algebra is substantially more abstract than high-school algebra, so many students have a hard time deeply understanding it, just like many students already bail out on high-school math. When I was a TA in college, I also observed that many students were not prepared for the fact that college-level math is fundamentally different from high-school ones. College-level maths has far less time for students to grasp the concepts through sheer brute-force practice. College-level maths requires students to focus on intuitive understanding of they key concepts so the students won't get bogged down by hundreds and hundreds of concepts or corollaries or theorems. Of course, high-school maths requires intuitive understanding too, but because high-school maths is so simple that many students get the intuition naturally so they are not aware of how important such intuitive understanding is.
This book used to help my students build intuitions: https://www.amazon.com/Algebra-Through-Geometry-Undergraduat.... It starts with 2D geometry to teach linear algebra, and then moves to 3D, and then 4D. The author also chooses to use calculations and constructions to prove most of the theorems instead of more abstract or algebraic approach.