For electrical phenomena (baring very very small scale, semiconductors) Maxwell's equations give you a huge amount of insight, especially the macroscopic varian

For electrical phenomena (baring very very small scale, semiconductors) Maxwell's equations give you a huge amount of insight, especially the macroscopic variant. You can see things like plasmons and polaritons (though obviously not their quantization). You won't really run into the atom stuff until you try to do something like calculate dielectric constants analytically, though self-energy is definitely a pretty easy trap to fall in even for macroscopic stuff.