I believe that power is passed along selectively to children, to help decide who the future elite are.... the "lucky" half are taught how to correctly tie their shoes... the other half end up with granny knots, which then signals to the elite this person is not one of them.
I was one of the granny knot population, always having to stop and re-tie my shoes... fortunately I learned the error of my ways about 3 years ago.
I think it's the same process as button shirts. This is a whole culture and social marker, but ultimately you can live your life without wearing them more than once a year.