The moment when you think you smell a fart, but nobody actually farted.
Your standing with a buddy and suddenly smell what you think is a fart so you say "Hey man, something smells like shit. Did you just blow ass?" And he says "Na man, you must be having a Craptical Illusion!"
When it feels like you've gotten rid of 5 pounds of crap, only to look and see it was only an ounce or so.
"I'd swear I just dumped a 5 pound loaf, but there's barely a slice in there..must be a craptical illusion."