I'm not sure I agree, but we'll agree to disagree. Think about it; you make a U turn, so you're going the exact opposite direction [180 degrees] from the way you were going before. Now, each turn is 90 degrees, so making two left turns would be 180 degrees, which would turn you back the way you were originally facing. So you only need one, to turn youself half way.
I seldom fling children from towers to improve their health.