hallucynation
What Little Miss vanPelt was experiencing during da infamous period when she was passing out lists of perceived faults to her fellow child-citizens around da neighborhood, explaining dat she wanted to make da world a better place for her to live in.
Linus vanPelt's older sister was experiencing a major "hallucynation" if she actually thought dat her informing everyone of his or her "shortcomings" would truly create a more-palatable-to-her "nation" --- as da enraged-and-snarlingly-charging-after-her-with-bared-teeth Snoopy demonstrated, some people don't appreciate having their "lesser angels" pointed out to them.
hallucynations
Nightmarish visions dat Charlie Brown, Schroeder, and Linus experience regarding da tempestuous pint-sized brunette in their neighborhood.
Having da neighborhood bullyess behave anti-socially towards you and always yank da football away when you're running up to kick it is enough to give anybody hallucynations!