One of the many contested perspectives on Lovecraft’s Yog-Sothothery is the idea that Azathoth currently sleeps and the world will end when he wakes. Lovecraft’s own works do not state this, so where might it come from? Perhaps our own tendency to live in a dream of purpose rather than a reality of explicit facts.
Lovecraft, particularly in his early work, was influenced heavily by the works of Dunsany. In Dunsany’s The Gods of Pegana, the creator deity Mana-Yood-Sushai fell asleep when he had created existence and was constantly lulled by a divine drummer becauce “if [the drummer] cease for an instant then MANA-YOOD-SUSHAI will start awake, and there will be worlds nor gods no more.”
Thus many Lovecraftians believe—not unreasonably—that Azathoth, a creator deity who takes no conscious part in reality and is lulled by musicians, was heavily based on Mana-Yood-Sushai.
As the human mind evolved to assemble points of experience into general theories and the human memory is imperfect, it is easy to see how someone who had read—or even simply heard—of Dunsany story might unconsciously conflate the two and not realise that Lovecraft didn’t say Azathoth dreamed reality.
In addition, Lovecraft was both a borrower and sharer, so his Yog-Sothothery (and that of his circle/literary descendants) knowingly contains potential connections to other works; for example, the “tekeli-li” of At the Mountains of Madness is taken from Poe’s “The Narrative of Gordon Arthur Pym”. Thus, Lovecraft’s work is also particularly open to treating similarity as evidence two things are the same. Thus some of those Lovecraftians who follow Derleth’s endeavour of fusing all the stories in “the Mythos” into a single universe believe Azathoth and Mana-Yood-Shushai are the same entity (in the same way that Yog-Sothoth and ‘Umr At-Tawil are the same entity and Lovecraft has different cultures use different names for Cthulhu).
With the internet enabling anyone to spread their ideas to the world, the people who have concluded Azathoth dreams reality can easily share this with others. While some people will dismiss it or do their own research, others will—consciously or not—add it to their mental image of Lovecraft’s universe. Thus the theory spreads, increasing the chances someone will encounter it not just once but multiple times; and, as we are wired to assemble data points into general theories, with each encounter with a new person advancing the theory we become more likely to accept it might be true ourselves.