Hallowe'en Puns

I just love putting the apostrophe in Hallowe'en every time.  Just a little cue to remind people of the origin.

How did Hallowe’en, of all holidays, come to be so strongly associated with puns? Other holidays have occasional puns associated with them. Valentine’s Day is a distant second in punning.  But nothing approaches October 31^st for riddles or posters about “a monster’s ghoulfriend,” “Boo-berries,” or a werewolf hiding in your “Claws-it.” Is it because we made it a children’s holiday because of the costumes and candy, and children do reach an age where they like that sort of simple wordplay?