The BuzzFeed Principle of Internet Content is that people will share your posts if your posts make it feel like sharing them constitutes a form of self-expression. This is one of the many reasons why effort put into a post does not correlate with the post's popularity.
it makes sense this is the most popular thing i've ever posted on the internet because it appeals to like 20 different groups at once (scenefurs, petplayers, pups, age regressors, people who just like cursed images) and they all relate to it. it's, like, the Ultimate Post