Thank you for the advice to learn more about auto racing.  I've lived in the Indianapolis area for over 50 years and have attended the 500 race 10 times.  The race is sometimes broadcasted locally as the "Annual Memorial Day Race".  The opening ceremonies begin with a invocation usually given by the Archbishop of the Catholic Archdioceses of Indianapolis in memory of our fallen military. There is a military honor guard ceremony in specific honor of Memorial day that concludes with Taps and an Air Force aircraft flyover in the missing man formation.  God Bless America and the National Anthem are performed.  In 1975 I marched with other Vietnam era vets in the 500 festival parade.  Does this speak to the significance between the 500 race and Memorial Day?  I don't know if you ever served in the military, but veterans remember and honor our fallen brothers and sisters.  Try to learn about Memorial Day.