Arianna Huffington shares the best career advice she ever received

Arianna Huffington has a theory about failure - it's something her mother taught her long ago.

"Failure is not the opposite of success; it's a stepping stone to success," her mother often told her.

Huffington says being comfortable with failure has proven incredibly useful in her career as a prolific book author, politician, and founder and editor-in-chief of The Huffington Post.

"My career, and I would say the careers of most people I know, has not been linear," she tells Business Insider. Most people's careers zig zag, Huffington says, and are full of unexpected moves and failures that lead to something better.

With a divorce, an unsuccessful gubernatorial race, and tons of book rejections under her belt, Huffington has overcome her fair share of personal and professional setbacks.

"I remember when my second book in my 20s was rejected by 36 publishers - by which time I was tempted to change professions - I went and got a loan from a bank and kept going," she says.

During a 2011 Sarah Lawrence College keynote address, Huffington said this was one of the lowest points of her life. Receiving a loan helped her "keep things together" while the book rejections rolled in until she finally got a 'yes.' After publishing her second book, Huffington went on to publish 13 more books, including her most recent, "The Sleep Revolution."

"I think our resilience is dramatically improved when we trust that often out of the biggest heartbreaks come the best things in our lives," she tells Business Insider.

She suggests people stop over-worrying about every little thing and instead do as the poet Rumi instructed: "Live life as if everything is rigged in your favor."