Three years after the first Harry Potter novel came out, J.K. Rowling told inquiring minds that there were about 1,000 students in Hogwarts.
But the math has not added up for fans over the years when it comes to Harry Potter's class size in particular. A screen grab from the film shows just 18 first-year Gryffindors, even though there should be about 35 when dividing 1,000 up by seven years and four houses, BuzzFeed notes.
A Tumblr user has a theory for why Harry's class is so small, and Lord Voldemort is likely to blame.
This is not the first time such a theory has been raised. Last year, Redditors on the Harry Potter subreddit discussed a similar notion.