When You're a Kid:
One day a year, kids get to dress like their favorite fictional character, walk around at night as they're told never to do, and receive candy for free. That's the Shangri-La a child would hallucinate and reach toward right before they pass out from a sugar rush in a world where Halloween doesn't exist. It also kind of sounds like a pedophile's perfect world.
When You're an Adult:
Halloween takes a turn away from costumes and spookiness when you reach the age where time spent working and sitting on your ass for eight-plus hours a day leads to an increase in laziness and pant size. Only kids can slam that much sugar in their heads and not end up feeling like a fleshy Katamari ball that propels itself with directional thrusters made of burps and farts. Halloween for adults becomes the one time a year a so-called "responsible adult" has something that somehow resembles justification for buying candy by the pound. Kids might show up! The candy must be purchased for the appeasement of the kids!
There ain't no kids. OK, maybe one party of an Iron Man and a kid dressed like a modern-day sexy vampire, but not enough to justify what appears to have been your cut after an armed robbery of Willy Wonka's factory. After months of restraint, months of holding back your most gluttonous, base instincts to slam every junky piece of candy within sight into your body, and months of using every excuse your brain can muster -- from weight gain to health risks to cavities -- there comes one day with a built-in pro-candy argument so convincing it obliterates every excuse you've got. Halloween is about candy, and if you don't buy candy you're technically a joyless asshole.
"Candy. Candy. Candy. Halloween. Candy. Candy."
*standing ovation from jury*