Bialik, 45, joined the hit CBS sitcom as Amy Garrah Fowler in its third season, which was first broadcast in 2003.
It turns out that the actor wasn’t on the hunt for a regular TV role and merely tried out in the hope of securing funding for health insurance.
Bialik, who has a doctorate in neuroscience, told Canadian talk show The Social: “I’m sure you all in the north can understand that I was running out of health insurance, because that’s not considered a right in this country.
"So I literally figure – I mean, I had a toddler and a newborn, and I had been a grad student and my insurance was expiring. This is a true story. And I figured if I can just get even a couple jobs like here or there, I’ll be able to get insurance again.”
Shortly after auditioning to play Amy, she found out she had been cast in the series, which eventually ran for 12 seasons and ended up being one of the most successful sitcoms in television history.
"I did not expect to be a regular on a television show,” Bialik said.
“I had been teaching neuroscience. I’ve tutored Hebrew. I’ve tutored piano. I wear a lot of hats, you know. And I eventually auditioned for this show called The Big Bang Theory, which I had never seen and it changed my life and I got insurance.”