When an actor who played a child role in one of your cherished Christmas movies appears in a recent film, it has a way of making you feel even more ancient than the physical signs of aging. Despite Oppenheimer being released in cinemas earlier this year in July, audiences are still grappling with the realization that David Krumholtz, who portrayed Bernard the Elf in the 1994 Christmas classic The Santa Clause, has a role in the movie.

Krumholtz first appeared in The Santa Clause at the age of 16, with his character, Bernard the Elf, becoming a fan favorite. The actor revealed in an interview with TIME that the internet’s reaction to his role was so intense that they had to ensure his return for the sequel. Krumholtz acknowledged that The Santa Clause is the film he is most recognized for.

Now at 45, Krumholtz adds another movie to his list of recognized works, with viewers of Oppenheimer taking to social media to identify him in the role of physicist Isidor Isaac Rabi, a friend of J. Robert Oppenheimer, portrayed by Cillian Murphy.

A TikTok user named Hannah Louise, who goes by the username @hdzialowski, shared her surprise on the platform upon realizing Krumholtz’s appearance in Oppenheimer. Her caption reads, “From Santa’s helper to American physicist who won the Nobel Prize in physics in 1944.” In another video, still processing the realization, she adds, “The way I could not concentrate on Oppenheimer when I realized… Bernard has made a career change, and I’m here for it.”

TikTok users and fans alike expressed their shock and recognition, with one user stating, “Omg, this is where I recognize him from.” Another added, “I FVCKING KNEW IT.” Fans took to Twitter to share their surprise, with one noting, “Oh shoot, I didn’t know that!” Another viewer mentioned noticing the connection in the theater and being “gobsmacked.”

Despite some expressing shock at the revelation, one user pointed out that they were surprised at how many people didn’t know about Krumholtz’s role in Oppenheimer, describing him as a “national treasure” who grew up in the same building in Queens as their girlfriend.