Ah yes, 4:20 is certainly a day to celebrate. Hitler - One of the worst human beings who ever lived was born, only to cause the destruction of countless human beings because of his horrid and ridiculous beliefs.
Also, a few dumbass attention whore losers from a little school called columbine shot up a bunch of people for no reason other then their own lameness. After killing 20 or so people, they assured everyone that they were pussies by turning the guns to themselves and pulling the trigger, in order to get out of the punishment that they deserved.
I see no reason to celebrate this day, unless you're a dumbass goth/pothead/attention whore loser who feels the need to validate a very sad day in humanities history.