Jessica Simpson Says She 'Freaked Out' Before Turning 40: 'I Am Accepting It Slowly'

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Jessica Simpson is opening up about turning 40.

The singer appeared on Sirius XM'S The Jess Cagle Show on Thursday, during which she revealed that she wasn't quite ready to step into the new decade of her life just yet.

Simpson, who celebrated her 40th birthday on July 10, admitted that she "freaked out" during the months leading up to her special day.

"I freaked out two months before I turned 40, not knowing that that age would even mean anything to me, but then it's like, oh but 41, 42," she explained.

"I've never calculated my age until now," she continued, adding that she's now "accepting it slowly."

To commemorate her 40th birthday, the mother of three shared a photo of herself fitting into a pair of jeans from her 20s.

"I have kept these throwback True Religion jeans in my closet for 14 yrs (I’m not exaggerating!)," Simpson wrote on Instagram, sharing a mirror selfie of herself rocking the denim, which she paired with a black and purple sweatshirt.

"I figured that since I’m in the final hours of my 30’s I’d give them another try, and hello 40, so nice to meet you," she added.

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The Dukes of Hazzard star also told Cagle that her decision to throw on the vintage jeans was "a really random thing."

"Because I haven’t put jeans on through the whole time, I've been in sweats. I am, like, embracing the quarantine life," she teased.

Simpson then explained that she enjoys looking at her past, sharing that she is "such a person who reminisces."

"I hold on to so many memories," she added. "I am so tragically romantic like that about my own self."

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Her ability to reflect on her past proved extremely helpful when writing her memoir, Open Book, which was released earlier this year. "Thank God I put a memoir out at 40 because it would have been 800 pages if I waited any longer," she laughed.

Simpson also recently celebrated another milestone: her sixth wedding anniversary with her husband Eric Johnson.

To honor the special day, Simpson shared a sweet tribute to the former NFL player on Instagram, saying that she married her "perfect soulmate."

"Eric Johnson, my Husband, I love you. 6yrs ago today I married my perfect soulmate," she wrote. "Our unity was written in God’s sky of colliding stars. Together we manifest dreams, nurture desire, and hold space. Destined, it always has been and always will be, forevermore."