to say "trick or treat" and then, "thank you." It is a very simple interaction and it drives me batty that a child would not master such a simple script. This isn't some intricate tea ceremony. It's 5 words you can memorize for an interaction centered on you getting free candy. It's one of my many Andy Rooney-esque complaints that I'm grumpy about. We are a SOCIETY, for goodness' sake. 

(Ofc, when push comes to shove, I'm a total softie and I'm not going to embarrass a trick-or-treater who may have a different cultural background or be young or shy or have special needs, etc. Obviously, part of our social compact is that it's not my job to call you out. It's just that there is a way things get done on Halloween and every child should learn it and respect it. Thank you for coming to my TED talk.. eerr and now you know the rest of the story or whatever Andy Rooney says.)