Most actors would jump at the chance to star in a sitcom pilot, even if they don’t know what that pilot’s future holds — and according to a tell-all book about “The Big Bang Theory,” one of that show’s stars, Johnny Galecki, was so reluctant to join the show “about nerds” that he turned it down a whopping five times before finally agreeing to play experimental physicist Leonard Hofstadter.

In Jessica Radloff’s 2022 book “The Big Bang Theory: The Definitive, Inside Story of the Epic Hit Series,” everyone involved with the series ended up speaking to the author, and the story about how casting directors Nikki Valko and Ken Miller worked alongside creators Chuck Lorre and Bill Prady to get Galecki involved is a real doozy. After the pilot was written (by Prady and Lorre), Valko and Miller had to cast both Leonard and his best friend Sheldon Cooper; ultimately, Jim Parsons wound up playing Sheldon, but apparently, Valko was honing in on Galecki right away. As Miller recalled to Radloff, “From the minute Nikki read the script, she was like, ‘Johnny Galecki is Leonard.'”

“He had gotten very fit and was doing a very sexy role on Broadway […] and played the gay lover of a closeted movie star,” Miller then explained, referencing “The Little Dog Laughed,” a relatively steamy play that Galecki was performing in at the time. “He was phenomenal, but he just felt like he had moved on from the nerdier roles. That’s what we had heard from his agent. Nikki called him like three times saying, ‘Please, please,’ but we kept hearing ‘It’s a pass.’ And then later on, his agent called and said, ‘What about Johnny?’ Nikki’s like, ‘He passed three times! What are we supposed to do?!’ I guess his agent just really believed in the show and the role, too.”