Good luck not feeling old when you see this.

Good Luck Charlie alum Mia Talerico headed off to her first day of her senior year of high school and reflected on how time has quickly flown by.

In pictures shared to Instagram Aug. 19, Talerico sported a pink, shoulder-free top and jean shorts as she posed with a sign that marked the momentous occasion.

“Last First Day!” the 17-year-old wrote in the caption. “Now I’m starting to feel old.”

And it’s not just the Disney Channel star who is shocked by how far she has come. Indeed, Talerico’s annual tradition of celebrating her first day of school has stunned fans who watched her on TV as a toddler.

“That’s so crazyyy we literally all [watched] her grow up,” one fan commented on last year’s post. Another added, “This is really the same charlie i grew up watching. im 22 now.”

Of course, Talerico—who starred in Good Luck Charlie as the titular role of Charlie Duncan from 2010 to 2014 alongside Bridgit Mendler and Bradley Steven Perry—is aware of how odd it is that she has aged in front of everyone’s eyes.