Harry Potter became famous for its characters as well as the intricate and complex world it takes place in. The world-building included Hogwarts as well, with its four houses.
Most attention was directed to Gryffindor since this was the house Harry and his friends belonged to. However, the other three houses were there as well, and multiple things about Ravenclaw prove that not everything about the wizarding world makes sense.
Not All Its Students Are Extremely Intelligent
Ravenclaw is the place for the most intelligent young minds. Except not all of its current or former students are as brilliant as one might presume. One such example is Moaning Myrtle. It's true that her personality might have changed once she became a ghost, but unlike the living Ravenclaws Myrtle is no genius. She's sneaky and good at spying on people, but if she was truly smart, she would have figured out a basilisk was after her.
Ravenclaws Form Cliques Too
Each house seems to have a certain clique of students who are more popular than others. Everybody loves them but is also envious of them sometimes. One might think that Ravenclaw, with its abundance of intelligent students, would avoid putting people into boxes, but Ravenclaw students still play the eternal favorite and outcast game that's so typical for schools.
Ravenclaw Has Evil Wizards Too, But People Don't Mind
This fact concerns both Ravenclaw and Slytherin. Unlike Slytherins, who are disliked by other houses, Ravenclaw has a good rep. But just like any other Hogwarts house, even Ravenclaw produced evil wizards or at least those who weren't nice people. One example is Gilderoy Lockhart who stole other people's heroic deeds and erased their memories. It's not on the same level as killing people but it's still far from good. Quirrell, who also attended Ravenclaw, was far worse as he made a pact with Voldemort himself. To be fair to Ravenclaw, it's not the house's fault if it sometimes contains a rotten apple.
They're Described As Attractive
Throughout the books, the Ravenclaws are described as attractive more than once. That poses the question of why is this information so important. It's true that the house has a fair share of good-looking students.
But if Ravenclaws value intelligence above anything else, it should be irrelevant whether or not they also are good-looking. Of course, the books are told from Harry's point-of-view and since he's a teenager when the story happens, he, of course, pays attention to pretty Ravenclaw girls.
They Separate Themselves
As smart people, Ravenclaws should know that interacting with students from other houses is the best way how to broaden their horizons to become even smarter. Yet they strangely seem to stick together. Maybe it's because the tower they live in is far away from other Hogwarts houses, but it is quite possible the Ravenclaws are just a tiny bit too choosy when they pick their friends.
It Has Very Few Memorable Characters
In the end, Luna Lovegood was the one who had the biggest impact on the story of all Ravenclaw students. There was also Cho Chang but the books (or Harry, really) didn't always portray her in the most positive light. Even though Ravenclaw is full of talented people, they never got as much space as people from other houses, most notably Gryffindor and Slytherin.
The Films Changed Ravenclaw's Colors
This is a small detail about the Ravenclaw house that only doesn't make much sense in the movies. In the books, Ravenclaw has two characteristic colors: blue and bronze.
Yet the films changed the colors to blue and silver even though it has zero impact on the story of the movies. The most plausible explanation is they changed the colors because silver looks better than bronze.
Its Main Trait Is Oddly Non-Specific
As said above, Ravenclaws value intelligence above anything else. It's their defining feature and the reason why Ravenclaw students are in Ravenclaw in the first place. Yet it doesn't really make sense since intelligence is an oddly non-specific character trait. All students must be intelligent to be able to finish their studies at Hogwarts, regardless of what house they end up in. On the other hand, the other three houses have much more specific character traits that aren't required to smoothly sail through Hogwarts - bravery (Gryffindor), loyalty (Hufflepuff), and ambition (Slytherin).
Rowena's Diadem Was Barely Hidden
It's clear from the books that J. K. Rowling put more emphasis on certain houses than on others. Ravenclaw got the short end of the stick. Even though Harry struggled to find most of the Horcruxes, the diadem that belonged to Rowena Ravenclaw was surprisingly easy to find. All it really took was Harry talking to Rowena's daughter Helena and persuading her to give him the diadem.
Their Symbol Is An Eagle, Not A Raven
People who first start with Harry Potter might be surprised to learn that the Ravenclaw's symbol is an eagle, not a raven. They might think it doesn't make any sense, and that's not entirely the case. Maybe choosing a raven as the house's symbol would be too on the nose, especially since the founder's name was Rowena Ravenclaw. Instead, the honor went to an eagle since the eagle symbolizes intelligence.