+1 for drainpipe theory! As a ChemE grad student I took an EE control class after basically forgetting all the circuits knowledge I learned as an undergraduate

+1 for drainpipe theory! As a ChemE grad student I took an EE control class after basically forgetting all the circuits knowledge I learned as an undergraduate (my high school didn't teach electronics and magnetism!). Water analogies were the only way I could do the problems with circuits. Drainpipe theory actually made me wonder what was ever so hard about that part of physics class...