Time for a change
Penn, who was just 32 when he made the change, was in the midst of a successful acting career that included staring roles in the big-screen Harold and Kumar films and on the small screen in shows such as "House" and "24."
Following a stint on the Barack Obama campaign trail during the 2008 presidential election, Penn gave up his Hollywood career for a chance to work for the Obama administration full time.
The actor-turned-political staffer told ABC News his decision was a personal one.
"I had friends who were over in Iraq and Afghanistan," Penn said in an interview. "I had buddies who had huge student debt, people who got kicked off their health insurance plans for one reason or another, and so that was my decision to get involved on a personal level."
During his time with the Obama administration, Penn served as an associate director in both the White House's Office of Public Liaison and the Office of Public Engagement.
The career switch was short-lived, however. After fewer than two years on the job, Penn returned to his acting gig.
Before the 1991 launch of his notorious daytime television talk show, Springer was serving the people of Cincinnati, Ohio, as its mayor. After five terms as a Cincinnati city councilman, during which he was forced to resign after being busted in an undercover prostitution sting, Springer was elected as the city's leader in 1977.
Springer spent just one year in office before launching his television career after a subsequent failed run to become Ohio's governor.
His run on the small screen has been much more successful than his political career. "The Jerry Springer Show" is in its 21st season and has led to a number of other gigs for the man known as the "Ringmaster," including a stint on "Dancing With the Stars" and a two-season run as the "America's Got Talent" host.
In her mid-20s, Stewart began her career as a stockbroker. Shortly after passing her securities exam in 1967, she became one of the few female stockbrokers on Wall Street when she was hired by the firm Monness, Williams and Sidel, according to the book "Martha Stewart: A Biography" (Greenwood Publishing, 2007).
Stewart had a successful stockbroker run, but gave up the job in 1973 when the economy turned sour. Shortly after that, Stewart began focusing her talents on renovating an old farm in Connecticut and building a catering business.
Since then, she has built an entire lifestyle empire that includes magazines, television shows, websites, home improvement products, home goods, pet products and crafts.
Her brand reaches 66 million consumers each month and has a growing retail presence, with 8,500 products in more than 38,000 retail locations.
That wasn't where her career began. Before becoming a media magnate, Robinson was an elementary school teacher in Newport, R.I., and Somerset, Mass. After 11 years of teaching, Robinson left the classroom for a sales management position with the New York Times Co.
She spent the next two decades working her way up the ranks, holding a number of positions, including president and general manager of The New York Times newspaper and senior vice president of newspaper operations for The New York Times Co.
In 2004, she became the company's president and CEO. She is credited with the creation and implementation of the newspaper's national expansion and the transition from an era of print journalism to one in which the Times distributes news and information in an increasing array of new mediums.
An All-American at Notre Dame University in 1966, the defensive end had an illustrious career with the Minnesota Vikings.
Page was named the league's MVP and defensive player of the year in 1971 and helped lead the team to four Super Bowl appearances.
He started preparing for his life after football while still on the field. While playing, he became a full-time law student, earning his Juris Doctor degree in 1978. The next year he joined a Minneapolis law firm that specialized in labor issues.
After retiring from football in 1981, Page really started putting his law degree and experience to work.
He became Minnesota's assistant attorney general in 1987 and was elected to the state's Supreme Court in 1993, a position he still holds today.
Before being elected a U.S. senator, Franken spent 37 years as a comedy writer, author, and radio talk show host. Most notable were the two decades he spent as a writer and actor for Saturday Night Live, for which he earned five Emmy awards.
After leaving the hit show in 1995, Franken began his foray into politics by writing books and hosting his own radio show.
Instead of just talking about his political opinions, Franken put his money where his mouth was and got elected to a U.S. Senate seat representing Minnesota in 2008. He currently sits on the Health, Education, Labor, and Pension Committee; the Judiciary Committee; the Energy and Natural Resources Committee; and the Committee on Indian Affairs.
The Austrian-born muscle man came to the United States in 1968 and spent nearly a decade as the most successful bodybuilder in the country, winning five Mr. Universe titles and seven Mr. Olympia titles.
Schwarzenegger parlayed his bodybuilding success into an acting career. In 1976, he won a Golden Globe Award for "Best Acting Debut in a Motion Picture" for his role in "Stay Hungry." But it was his portrayal of Conan the Barbarian in 1982 and The Terminator in 1984 that really launched his superstar status.
Over the next two decades, Schwarzenegger starred in more than 20 movies that collectively grossed more than $1.6 billion.
Schwarzenegger then gave up his leading-man status for another career move, this time jumping into the political in arena. He was sworn in as California's 38th governor on Nov. 17, 2003.
Schwarzenegger spent eight years in office, focusing on reducing California's greenhouse gas emissions, increasing the minimum wage and updating the workers' compensation system.
Now that he's out of office, Schwarzenegger is returning to his acting roots. He is set to star in four movies over the next two years, including "The Expendables 2," which is set to premiere this summer.
In the early 1970s, Natori landed at Merrill Lynch as the first female vice president of investment banking.
"But the desire to be president of the firm wasn't in me," she said in an interview with CNN. "Just making money wasn't enough."
Natori left her Wall Street job in 1977 and immediately launched her own line of lingerie, which made more than $300,000 in just three weeks.
More than three decades later, the company has grown into a lifestyle brand that includes four different lingerie collections, the Josie Natori ready-to-wear collection, home, fragrance and eyewear.
Chad Brooks is a Chicago-based freelance business and technology writer who has worked in public relations and spent 10 years as a newspaper reporter. You can reach him at email@example.com or follow him on Twitter @cbrooks76.