But that doesn't mean fans don't still have questions.
One Potter fan recently pondered a question that you might not have even known you had: Why were there so few people in Harry's class?
"For years, we’ve all wondered how there can be 1,000 students (according to J.K. Rowling) in Hogwarts when there are only a handful of students in Harry’s year," Tumblr user marauders4evr wrote. "The math doesn’t add up. We’ve all just assumed that it was an error."
Marauders4evr has a point.
In the "Harry Potter and the Sorcerer's Stone" film, Percy Weasley can be seen escorting no more than 20 first year Gryffindors to the common room.
And throughout the books, Rowling doesn't mention many other characters besides Neville, Dean, Seamus and a few other memorable names.
But in a 2000 interview, Rowling said about 1,000 students attended the school during Harry’s time.
If there were 1,000 students, seven years and four houses, each house should have about 35 students per year. That's significantly more than readers are led to believe are in Harry's class.
"But what if there’s normally dozens of students in each house, in each year? What if Harry’s year was the exception?" marauders4evr challenges.
And then the fan answers that very question:
"What if there were less students in the Hogwarts Class of 1998 because the period when the other kids would have been conceived (1979-1981) was when Voldemort’s reign of power was at its peak? Between the dozens of adults who joined the Order, the dozens of civilians who were killed in Death Eater raids, and the dozens of adults that didn’t want to bring a child into the world, just then. It’s actually entirely possible that there was a baby drought for a few years in the wizarding world, leading to a smaller class size a decade later."