Let me try another approach to your dilema. It is correct that a switch simply breaks the flow of electricity, usually in the 'hot' or black wire. If you connect the power wire (black) to the bottom screw of a switch and again to the top screw you then have an interupter in the wire. When the switch is 'on' the wire is connected, when it is 'off' the wire is broken.
The neutral (white) wire continues uninterupted. We sometimes run a wire from a ceiling box to a wall box to be switched. We use romex cable which contains a black, a white, and a bare grounding wire. In this case we make the white wire part of the power loop, black comming down to the switch and the white going back. However, in this case, we are supposed to paint or use black tape on the wire to indicate it is a power wire. That white wire that is painted black returns the power to the ceiling box where we mount a light fixture, fan, etc.
Only one question on this test, is it clear as mud?