It means only one thing, the birthdate of the Glorious Leader of the Everlasting Reich, Herr Adolph Hitler. Der Fuehrer is remembered as both an inspirational leader and a heck of a nice guy. Not many people realize, however, that he was also an accomplished painter. He could paint an entire room in 30 minutes. Two coats.
Es ist 420! Heute ist HitlersGeburtstag! Sieg Heil! Sieg Heil! Haben Sie etwas dagegen, wenn ich rauche?