Mark Ruffalo says he 'almost quit' '13 Going on 30' over the Thriller dance that took him hours to learn

• Mark Ruffalo said he spent hours trying to learn the "Thriller" dance for "13 Going on 30."
• While promoting "The Adam Project," Ruffalo and Jennifer Garner were asked to reflect on the scene.

You may love watchng Jennifer Garner and Mark Ruffalo perform the dance sequence in 2004's "13 Going on 30," but it's a moment that haunts the "Avengers" actor a bit.

"She had to drag me onto the dance floor," Ruffalo told Fox 5's Kevin McCarthy while promoting Netflix's upcoming sci-fi movie "The Adam Project" where he reunites with Garner.

"It took me six hours to learn what she learned in about six minutes," he continued. "She was so good at dancing and I was so bad."

"I almost quit the movie," Ruffalo added, laughing.

In the 2004 movie, Garner's character, Jenna, starts to perform the dance to Michael Jackson's "Thriller" by herself to save a dull work event. When she spots her childhood friend Matty (Ruffalo), she convinces him to awkwardly join her on the dance floor.

Matty starts off a bit shaky, but then gets in the groove as the two successfully encourage a group of people to join them, saving the party.

Ruffalo said he didn't need to act much in those first few moments, revealing, "Whatever Matty was experiencing in that, was actually just me."

"We had to talk him into staying," Garner, who was paired with Ruffalo for the interview, told McCarthy. "We had done all this rehearsal and then we finally rehearsed the dance and he was just like, 'This isn't for me. I'm not doing it.'"

By the end of interview clip, Ruffalo had covered his face with his hands.

Garner reached out to Ruffalo to make sure he was OK.

"The Adam Project," streaming on Netflix Friday, follows Adam (Ryan Reynolds) who goes travels back in time to consult his father (Ruffalo) to try and prevent a catastrophic future.