technical explanation for cable direction?

I always connect my cables according to the arrows on them or the manufacturers recommendations. (Why take a chance that ignoring them MIGHT make my system sound less than it could?) However, I have an EE degree from the 70's, and frankly, I KNOW that audio signals are only AC and I cannot for the life of me believe that it could possibly make a difference. I believe that the current in an audio cable is actually "performing a circular dance", at the speed of the highest frequency contained at the time, between its ends, and if you could measure or glimpse the direction of electron flow at any one instance, it would be going one direction or the other, changing instantly (according to the frequencies contained) and averaged over 1 second or minute or day would be zero. Current DOES NOT flow from the amp into the speaker and stay there. Current flows back and forth through the voice coil of the speaker back to the amp in both directions. If you connect an oscilloscope to the + & - of any audio cable you can "see" this balance. (identical shaped waves above and below the zero line, representling voltage in each direction) SO: Do I know just enough to be confused and not enough to know some detail that makes cable direction meaningful? I really think its just BS. Whew! please help