Tinstafl explains it in much the same way my old instructor would. May I venture a suggestion for True North, speaking as a non instructor (low hours PPL). At some point in your flying, if funds and logistics permit, try flying dual in an aircraft which normally requires more rudder inputs than a C150/152. Some nosewheel aircraft (eg Firefly, Pup, Robin) and probably most tail draggers would qualify, and the one I have experienced which hammers home the concept is the Tiger Moth. Persuade someone to buy you one of those gift vouchers for a Tigger trial as a Chrissie present. 30 mins dual with an experienced Tiger QFI should illustrate the point fairly neatly. Tell him you are not concerned (this time, at least) with learning Tiger checks, departures or landings, and concentrate instead on S&L and a few balanced turns. Then go back to the Cessna and see what happens.