I was telling a friend of mine that although I come from a Mexican heritage, my family has never celebrated Cinco de Mayo. When I once asked my mom why we never did anything special for May 5th, she responded that September 9th, which is the Mexican independence day, is really more important than Cinco de Mayo so that date is more important to Mexican's.
However, our family has never celebrated Nuevo de Septembre either. I guess that's because we're American's. We always celebrate the 4th of July.
Happy Cinco de Mayo, anyway!!