Jim Parsons
Looking back at his college years, Parsons pokes fun at some of his choices. “I majored in radio and television,” he laughs. “I don’t know what I was planning.” But it soon became obvious that there was only one thing he wanted to do. “I had a friend who majored in theater, and I watched him and realized how much I missed it. I knew then that I had to try.” His last “real” job before grad school at U. of San Diego/The Old Globe Theater was for Microsoft’s city guide, Sidewalk, where he worked as an assistant. “There were many days spent on unemployment,” he says, “but I never felt too lost in faith that things would work out.”

Johnny Galecki
Galecki has acted professionally since age 7 and when cast as a regular on “American Dreamer” at 14, moved to Hollywood to live by himself. Although he stayed out of trouble, Galecki admits it wasn’t purely due to his impeccable work ethic. “I didn’t know a soul in Los Angeles, except for the people I was working with,” recalls Galecki. “I probably, given the opportunity, would have succumbed to any peer pressure.” After a solid 17 years in the business, Galecki took a few years off in 2005 to see what else he could do. “A friend of mine suggested I design bathrooms,” he says. “I honestly started to consider that a little bit. I’ve even toured the Kohler factory.”

Kaley Cuoco
Though Cuoco got her start at an early age, she briefly considered other career options. “I played tennis for a long time,” says Cuoco, who used to be a ranked amateur in the Southern California Tennis Assn. “When I was younger, I wanted to possibly play tennis or work with horses, but I landed on a hit show and stopped that dream. I was like, ‘I’ll take this. This is better.’ ” One of Cuoco’s first roles was playing young Claire Danes on “My So-Called Life.” “It gave me a taste of what it was like to be on a set, and I fell in love with it. I knew it was the life for me.”

Simon Helberg
The son of actor Sandy Helberg and casting director Harriet Helberg eschewed acting as a child, instead focusing on karate and music. “I was a black belt in karate by the age of 10. I was a disciplined, obsessive child and spent a lot of time indoors doing things,” says Helberg, who also plays the piano professionally. A role in “The Importance of Being Earnest” as a high school senior put Helberg on his current path. “I kind of realized that it was inside of me, that I really wanted to do it instead of just watch.”

Kunal Nayyar
Indian native Nayyar found at an early age that he had a real knack for badminton. “It was the only sport where I couldn’t really get hurt, and that helped,” jokes the actor who played at club level in New Delhi. Nayyar moved to the States in 1999 to pursue a degree in business, but decided acting was his calling. “I realized that I loved being on stage more than I did being in a boardroom trying to sell something I didn’t give a shit about,” he says. He’s also newly married to Miss India 2006, Neha Kapur. “Actually, the joke’s on her. She thinks I’m a lot more charming than I am.”

Melissa Rauch
The stand-up comedian has President Bush’s daughter Jenna to thank for her career in showbiz. “Say what you will about the Bush administration, I kind of owe everything to them,” says Rauch, whose one-woman show “The Miss Education of Jenna Bush” led to appearances on VH1’s “Best Week Ever,” a guest role on NBC’s “Kath and Kim” and what was supposed to be a one-off on “Big Bang.” “After that episode they said, ‘Well, come back for another one.’ And then it blossomed into this,” she says. “It’s an actor’s dream come true that it ended up being more than it was.”

Mayim Bialik
It may come as a surprise that out of the entire cast, it’s the former child actor who has the most extensive knowledge of science. “I don’t know if it’s little-known, but I have a Ph.D. in neuroscience,” says Bialik, who writes her own science dialogue. “More of a little-known fact about me is that I’m a comicbook nerd.” When not indulging her inner geek, the mother of two also writes a blog about parenting. “I just became this unofficial spokesperson for attachment parenting. Kveller (a website on Jewish parenting) gave me my own blog and I have a book coming out in March. It’s kind of crazy.”

Gals grow new ground | Authenticity apparent in scientific scenarios | Timeslot shuffles don’t slow ascent | Syndie ratings strong for ‘Big Bang’ | Cast confessions