Even though it's not a holiday.
And it's not anyone's birthday.
And no one did anything special or out of the ordinary.
You have to have a celebration just because. Just because your mom is CRAVING CHOCOLATE. WITH SPRINKLES. IN ICE CREAM CONES. AND CUPCAKE FORMAT.
And you know what? Who are you to argue?
Reid? He likes to party too. Preferably on a daily basis.