While working on The Waste Land T.S. Eliot wrote the line “those treasures over which creeps the beneficient spiders.” That didn’t seem right. Next he tried “nor in memories which will busy beneficient spiders.” No. What about “industrious spiders”? What if they were “kindly spiders.” No, he thought, let’s keep them “beneficent.” And let’s make it “spider,” singular.
At last he settled on “or in memories draped by the beneficent spider.” Instead of many spiders picking and sorting through various strands of memory, it’s just one spider, spinning out memories, or covering them in a web, or maybe some third option.
Plausibly one could go insane looking through all the revisions of Eliot’s poem and trying to figure out what each of the different changes meant.