Caitlyn Jenner is now living as "her true self" following years of denying who she really was - NZCity

Speaking in a behind-the-scenes video, which has been obtained by PEOPLE, and includes quotes from Caitlyn's tell-all book, she said: "Imagine denying your core and soul. Then add to it the most impossible expectations that people have for you because you are the personification of The American Male Athlete. After a lifetime of secrets ... and a long personal struggle ... Caitlyn Jenner is finally learning to live as her true self."

And Caitlyn - who has daughters Kendall, 21, and Kylie, 19, with ex-wife Kris Jenner - has admitted time has been "moving so quickly" for her over the past few months, she is glad to be able to take some time to "reflect" on her major transformation.

Speaking previously, the 'Keeping Up with the Kardashians' star said: "Things have been moving so quickly that it will be nice to slow things down a bit and take the proper time to reflect on this journey. I couldn't pick a better team ... to make sure this story is told with a lot of honesty and care."

Caitlyn first announced she was working on the memoir in January 2016, and took to social media in November last year to reveal the details of the upcoming publication, and her excitement at the project.