7 books. 7 years of school. 7 Horcruxes. 7 Weasley children. The 7 potters. 7 tasks to the Sorcerer's Stone. 7 is Harry's Quidditch number. Gryffindor House is on the 7th floor. Lily and James began dating in their 7th year. 7 secret passages in Hogwarts. "The House of Black" Has been in the family for 7 generations. 7 players to a quidditch team. The Room of Requirement is on the 7th floor. Harry and Neville were born in the 7th month.
Ginny was the first girl born in 7 generations. 7 dragons mentioned in the series. 7 Defense Against the Dark Arts teachers. 7 classes in Harry’s first year. Harry and Ron were spotted by 7 muggles while driving the flying car in their second year. Dumbledors Army went through 7 doors in the Ministry of Magic in the Order of the Phoenix.