Well, the concept of national holidays, in this case "Fiestas Patrias" is a little difficult of define, but i think that the definition of a holyday so important like this one depends of the vision of each one. For me, is a big oportunity of travel to my city and spend more time with my family, in a context of joy and fun, where is no posibilite that miss the jokes, the music and the party. In my case i have very good memories of a national holiday: two years ago with some good friends organize a delicious "asado" accompanied with music and a lot of drinks. The party started at 8 P.M. and ended at 10 A.M when the last "survivors" of this excelent celebration were exhausted. That was a very good September 18th.
This year was more boring, but in any case i ate too much and enjoy the day with my family.