We've been schooled!
The cast of Glee may have been playing high school students for several years now, but in reality, prom season was a long time ago for most of them.
Hitting the big 3-0 last year were Cory Monteith and Mark Salling. Both born in 1982, they surprised us when we learned they had three decades under their belts.
Bet you wouldn't have guessed that Harry Shum Jr., who turned 31 yesterday (Happy Birthday, Harry!), tops the list as the oldest actor who plays a high school student on the show.
And on the opposite end, at 22, Chris Colfer is the baby of the group.
Check out our gallery (above) to find out how old Naya Rivera, Kevin McHale, Dianna Agron and the rest of the Glee cast really are!
'Glee' by the Numbers: How Old Are the Cast Members, Really (GALLERY)?