Next year, the pioneering supernatural drama "Buffy the Vampire Slayer" turns 25 -- a milestone that series star Sarah Michelle Gellar was not expecting to come so soon.

"Really?" the 44-year-old actress gasped when speaking to Us Weekly about the upcoming anniversary. After blinking several times, she remarked, "Wow. I'm old."

The "Buffy" pilot premiered on March 10, 1997, on the WB, now known as the CW, and aired there for five seasons. The show ran for seven seasons -- with its final two seasons airing on UPN and its series finale dated May 20, 2003 -- and produced another successful spinoff, "Angel."

Gellar spoke of the show's long-lasting legacy and expressed, "I think, as an actor, you always want to create something that holds up, that stands the test of time, that makes an impact. ... We did that with 'Buffy.'"

Calling the series a "golden ticket," the Golden Globe nominee admitted that she doesn't want to see "Buffy" rebooted.

"When you do something really well, you should leave it," she remarked. "And if other people wanted to do it, I think that’s awesome and incredible. But I don’t know. Why mess with something when you’re really happy with the way it turned out?"

Gellar revealed that she would be open to a reboot of her 1999 movie "Cruel Intentions," as it was a retelling of the 1782 French novel "Dangerous Liaisons."

The "All My Children" alum also revealed she's been binging "Buffy" with her two children, whom she shares with longtime husband Freddie Prinze Jr., because they are finally old enough to watch the show. Charlotte is 11, and Rocky is 8.

Gellar said she has no qualms about her kids watching the series' earlier episodes, but admitted that once the show follows Buffy to college in the fourth season, "I have to sort of cherry pick which ones [are appropriate], 'cause they’re still young."