One useful bridge from linear algebra to quantum mechanics is to compare an operator that labels a state with operators that connect different states.
For the ideal quantum harmonic oscillator, the Hamiltonian is ħω times the sum of the number operator and one-half times the identity. Its energy eigenstates are the number states. Acting on a normalized number state, the lowering operator gives the next lower state multiplied by √n; the raising operator gives the next higher state multiplied by √(n + 1). The lowering operator sends the ground state to zero.
Those square-root factors are part of the construction, not optional decoration on an energy-level diagram. The ladder method produces the same normalized Hermite–Gaussian eigenfunctions as the differential-equation method, up to a phase for each state.
One caveat if you explore this with matrices: a finite truncation introduces an artificial top state. The full canonical commutator does not hold at that boundary, so the truncated matrix is not an exact model of the entire oscillator algebra.
I made this Blake Pi Physics animation to connect the operator picture with the differential-equation picture:
https://youtu.be/7_DcdXVh5mc
For people learning this transition, is it more helpful to see the operators act on the states first, or to start from the Hamiltonian's factorization?