Of all the things we've ever considered when it comes to Hogwarts, class size isn't really one of 'em. We've probably been a bit distracted by the ideas of turning yourself into a cat and seeing Snape wearing Neville's gran's fancy Sunday hat with a raven on to think about the logistics of things, really.
But the latest Harry Potter fan theory has drawn everyone's attention to the fact that actually, class sizes in Harry's year are teeny tiny, and the possible explanation for the low numbers of students is really heartbreaking.
First things first - in an interview back in 2000, JK Rowling said that Hogwarts had an overall pupil count of about 1000 students.
But the scene in Philosopher's Stone below shows prefect Percy Weasley taking the first-year Gryffindors to their common room, and as you can see, there's not exactly a classroom full.
Buzzfeed reckons there are only about 18 students in the whole of the Gryffindor class, and when you think about it, there's not many names that you're familiar with apart from the big three, plus Neville, Dean and Seamus.
There are seven years, and four houses. So when you sit and work all the numbers out from that, there should be about 35 Gryffindor students in Harry's year - almost double the 18 we see in the film.
Tumblr user marauders4evr has a theory though, and it's guaranteed to break your heart. According to her, there's fewer kids in Harry's year and his surrounding years as a result of the loss of life in the brutal war against Voldemort, which took place roughly between 1970 and 1981.
Yep, 11 years before Harry entered first year as an 11 year old. The numbers make sense.
We weren't emotionally ready for this one this morning. Sob hiccup blub.
What are your thoughts on this theory? Reckon it's JK Rowling being a genius again, or just a super sad coincidence? Let us know with a tweet to @Sugarscape, oooh and don't forget to add us on Facebook too after you've checked out the bonus vid below.