Good luck with feeling young after learning that Mia Talerico is in high school.

That's right, the child star who played the titular tot in Good Luck Charlie just started the ninth grade, effectively making millennials and Gen Zers everywhere feel old AF. Mia marked the milestone with a back-to-school photo shared on her Instagram Aug. 23, in which she was seen holding up a chalkboard sign reading, "First Day 9th Grade. 8-21-23."