There once was a slug that was convinced it was a peacock. His other slug friends seemed to corroborate this belief—whether they really agreed with him or whether they were just humoring him will never be known, but in his home section of the forest everyone agreed with him that he was in fact a peacock with a beautiful big feather fan of iridescent decadent color. In fact, his friends told him he had the finest such fan that ever existed.
All was fine and good, albeit a little ridiculous, until the day the slug came to the edge of the forest and saw a couple of real peacocks spreading their fans, their colors shimmering in the sun.
He called out to them, asking them what they thought of his fan. The finest ever and all.
They laughed. “Fan? You have no fan. You are not a peacock, moron. You are a slug.”
He protested otherwise and came crawling up to argue the point with only a trail of slime behind him, no lovely feathers. The peacocks laughed louder at his insistence, but when the joke got old and they realized he was quite crazy and convinced and unwilling to listen to reality, they took off and flew away rather than continue to waste their time.
Still operating under his delusion, the slug returned to his friends in the forest, indignant at having been told the truth. He continued to insist he was a peacock with the finest fan in the land, but maybe, just maybe, some of his bitterness at the peacocks’ laughter came from that nagging little voice in the back of his slimy head that they’d been right and he really was just a slug in the forest.
(And maybe, just maybe, there’s nothing wrong with being a slug in the forest so long as you don’t try to be something else, let alone insist the real peacocks indulge your illusions…)