‘Grey's Anatomy’ series creator Shonda Rhimes recently opened up about which character from the hit medical drama was based on herself.

As she wrote in her "Year of Yes" book, Rhimes admitted about having many insecurities while she was growing up. This has been the main reason why she went on to create the character of Cristina Yang (Sandra Oh) who can be deemed as her alter ego.

"During my darkest hours, my quietest saddest moments, my loneliest times, writing Cristina Yang fortified me. I leaned into Cristina, wrote her more eloquently, colored her more brightly, drew outside the lines," she wrote.

The executive producer also revealed how Cristina helped her in expressing her goals, dreams and fears both on the medical show and in real life.

"She did not want to get married. She had a genius that she chased. She loved her work. I gave her a strident desire to not have children because while I adore children, I wanted to watch her fight that feminism battle and win," she added.

Oh made the final decision to leave the hit ABC series a few seasons ago. As pointed out by the actress, she felt it was the right time for her and Cristina's story to end.

During the time, Rhimes was also going through difficulties letting the well-loved character go.

Following Oh's departure from ‘Grey's Anatomy’ after the tenth season, Rhimes said that she will certainly miss the character, and even admitted that she is uncertain of how she will cope.

Meanwhile, the series creator also noted that Meredith Grey's (Ellen Pompeo) personality has also been derived from her own traits in some way.

However, it was the character of Cristina which she believed was "the walking validation of her dreams." Interestingly, Rhimes even included a short conversation she had with Oh in the acknowledgement page of her ‘Year of Yes’ book.

"I stared at her a long beat. 'Sandra,' I said slowly. 'YOU said it for me,'" she wrote.

In addition, Rhimes also sat down with Cosmopolitan to discuss her favorite life lessons, placing more emphasis on knowing what one should want and dreaming big.

“Don't ever say out loud again that you're going to dream small!' So many women look for permission. Men don't — they just do it…,” she said. “Stop worrying people are going to think you 'like yourself too much.'"

Rhimes’ "Year of Yes" has now been made available in bookstands in the United States.