Can you believe The O.C. [1] is officially 15 years old? Neither can Rachel Bilson [2]. On Sunday, the actress behind Summer Roberts got incredibly nostalgic about the show's big anniversary. "15 year anniversary of The OC. I can't believe it," she wrote alongside a cute photo of the cast [3] on Instagram. "I also can't believe I wore a skirt I got at a thrift shop as a shirt 😳 #ifeelold #survivedtheschwartzsharkattack #welcometotheocbitch #ew 🙏🧡"

The show first premiered on Aug. 5, 2003 on Fox and ran for a total of four seasons before ending in 2007. Since then, Bilson has come a long way [4] including starring on The CW's Hart of Dixie and welcoming a daughter named Briar Rose with Hayden Christensen [5] in 2014. Is it too soon to ask for a reboot, or at least a cast reunion?