I've heard it said that you can't fully understand how a thing works until you are capable of completely taking it apart and then reassembling it back together again in it's original working condition.
Maybe that's a necessary condition, but it's certainly not a sufficient condition.
I've disassembled (and reassembled) quite a few things that I didn't fully understand. I did have to take notes for some of the more complex devices, though, or I'd have never gotten the wires reconnected properly.
