You get winded from knocking on the door.
You have to have someone chew the candy for you.
You ask for high fiber candy only.
When someone drops a candy bar in your bag, you lose your balance and fall over.
People say, "Great Keith Richards mask!" and you're not wearing a mask.
When the door opens you yell, "Trick or..." and you can't remember the rest.
By the end of the night you have a bag full of restraining orders.
You have to carefully choose a costume that won't dislodge your hair piece.
You're the only Power Ranger in the neighborhood with a walker.
You avoid going to houses where your ex-wives live.
Source: Internet