As a friend has proved with a Fozgometer, levelling your cart by setting azimuth with a bubble on the top as we all do does not always give the best result, as the diamond may not be quite straight in the cantilever.
“Music has always been a matter of energy to me, a question of fuel. Sentimental people call it inspiration, but what they really mean is fuel. I have always needed fuel. I am a serious consumer. On some nights I still believe that a car with the gas needle on empty can run about fifty more miles if you have the right music very loud on the radio”
Hunter S Thompson