My dad was an electrician, but he never explained what was going on with the wires. Maybe that's because he understood it so well he couldn't imagine it needed explaining. Or maybe he thought, “You take this wire from here and put it there - what's to explain?” Anyway, looking at the wiring in the walls every day completely mislead me about electricity.
If you could see inside your walls, you'd see what looks like one wire connecting wall outlets to switches to ceiling lights (see Figure 1).