On a related note, Graph Theory is one of the top reasons to learn Linear Algebra. All graphs (included directed, weighted, and multi-graphs) can be represented

On a related note, Graph Theory is one of the top reasons to learn Linear Algebra. All graphs (included directed, weighted, and multi-graphs) can be represented intuitively by adjacency matrices, and matrix operations often end up being meaningful in terms of the graph they represent. Seeing the connections between a graph and its matrix helps to understand both of them, and being able to switch back and forth between mental models is often useful. For example, Markov Chains are the go-to tool in many fields of modeling, are most easily thought of as weighted graphs, and are most easily manipulated as matrices.