For the non-Seinfeld fans Festivus is a holiday created by George Costanza's father Frank (who played by the late great Jerry Stiller). Festivus is the festival for the rest of us.
You have an aluminum pole which is not decorated with anything
You sit down to dinner with the family
Your air your grievance for the year especially those sitting at the table who disappointed you
You demonstrate feats of strength
It aired on December 18, 1997 and since then many Festsivus fans celebrate it every year.
Maybe next year I'll remember to. Will you remember to too? Or did you?