I always bring up the example of how the atomic nucleus is taught:
Elementary school: Stuff is actually made out of tiny little balls you can't see.
Middle school: Those tiny little balls are actually atoms, they consist of a positively charged core of protons/neutrons with negatively charged electrons flying around it. An atom is the smallest thing matter is made of. (Rutherford model)
High school: Those electrons don't just fly around, they actually orbit within specific energy levels. Also they're not really particles, but waves, but also particles, all at the same time. Also subatomic particles exist. (Bohr model)
University: "Electron orbits" are actually orbitals defined by the wavefunction of those electrons, like probability distributions. (Quantum Mechanics)