I've noticed some folks have a peculiar inclination to tell gruesome stories when a particularly toothsome dessert is lofting into view. This bad habit tends to cause other people to not eat all of theirs, and eventually they offer it to the teller of that grody story, as the only one with an appetite left at the table. "DO you want the rest of my pie?"
Hmm.
Funny how these bad habits can get reinforced.
(walks away, whistling gently...)