They were just learning to instant-message their friends when Harry Potter got his first owl from Hogwarts School of Witchcraft and Wizardry.
As they were using their new licenses to drive to school, Harry was meeting his estranged godfather Sirius Black.
When they were already looking up old boyfriends and girlfriends through MySpace and Facebook, Harry was getting his first kiss, battling evil wizards and discovering a prophecy about his future.
For Sarah Harper, a 19-year-old student, reading the series through her adolescence was like growing up with Harry.
"At 15, his experiences were very similar to my experiences in a weird way. Except I wasn't fighting evil wizards all the time," Harper said.
Many readers feel a similar connection, said Nancy Pearl, author of "Book Lust."
"One of the things for people who did come of age as Harry came of age is that the increased complexity of the books made it worth their while to keep reading," Pearl said.
She compared the Harry Potter books to other cultural milestones, such as "Star Wars" in the 1970s.
"It's as much a cultural icon as cell phones and the Internet," Pearl said.
Meeting someone who has not read the books, or at least watched a movie, is weird for Terra Morgan, a 21-year-old at the premiere.
"It's social more than anything else because everyone knows about it," Morgan said.
"Harry Potter is part of a shared cultural heritage. It serves as a touchstone for their experience that they can look back on, and binds them as a group culturally and generationally," said Philip Nel, an associate professor of English Kansas State University who teaches a course on Harry Potter and wrote "J.K. Rowling's Harry Potter Novels: A Reader's Guide."
As the hours countdown to midnight Saturday, members of the Potter generation are preparing for the end of a decade-long affair.
Some plan to reread the series. Caroline Reaves, a 19-year-old student, sped through all 885,943 words of the first six books in 24 hours to prepare for book seven. She said she might slow down her reading speed to savor the last book.
Emerson Spartz, creator of the popular Potter site Mugglenet.com, said the last pages of the books would be bittersweet.
"Each page is going to be like a death clock counting down," Spartz said.