@Russelli While knowing the theory of semiconductors would be good I'm not sure its entierly the best example of what I mean. It doesnt have a huge application on understanding novel circuits.
I think a better example might be how many EEs dont fully understand maxwell equations. I tried to explain how all electric circuits have a magnetic circuit dual to a room full of experienced electrical engineers. None of them could even understand the simple concept that magnets store energy in their magnetic field that under special circumstances can be extracted that is in many ways no different than a discharging inductor or even an inductors dual, a battery/capacitor.
They were all taught you cant extract energy from a magnet, and while that is true under normal circumstances there are special circumstances where you can, and because the idea of "you cant extract energy from a permanent magnet" was drilled into their head they couldn't accept the very obvious truth that this was incorrect under certain conditions.