Beyoncé Celebrates Turning 40, Says She's 'Grateful to Be Grown' in Open Letter

Beyoncé is embracing 40 with open arms.

The singer, who celebrated her milestone birthday on Sept. 4, penned a letter to her fans on her website Thursday, reflecting on her personal growth and lessons learned so far.

"This is the first year that I really understand what it means to be alive and to live in the moment," Beyoncé said. "It's the first time that I have an understanding of how fragile life truly is, how hard life can be at times, and therefore how important it is to stop and smell the roses during the good times."

"I thought I knew that at 21 or 30...but I didn't," she said.

The "Flawless" singer released her first album, self-titled, with Destiny's Child band members Kelly Rowland, LaTavia Roberson and LaToya Luckett in 1998, followed by her first solo album Dangerously in Love in 2003.

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As she continues to grow and change as a person, Beyoncé says she's been able to soak up joy on a deeper level than ever.

"The more mature I become, the more I understand and the deeper my joy grows. There's a freedom and liberation knowing that I've made it to the other side of my sacrifice," the 28-time Grammy winner explained. "I'm finally giving myself permission to enjoy the seeds I've worked so hard to plant my whole life."

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In her letter, the superstar also took aim at the old-fashioned notion that life goes downhill for women after 40.

"Whoever tried to condition women to feel that we are supposed to be old or unhappy when we turn 40 got it ALL THE WAY F'd UP. This has absolutely been the best I've felt in my life," Beyoncé said, adding, "I'm so grateful to be GROWN, GROWN!"

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The mom of three also thanked her Beyhive fanbase for sending birthday well-wishes and their continued support of her career.

"As Virgo Season comes to an end, I hope my fellow Virgos had great birthdays," the "Gift From Virgo" singer said.

"I'm so thankful for every inspiring human who took the time to send me all the beautiful messages. I cried tears of joy and was covered in chilly bumps," she continued. "Your videos, your posts, your countdowns, your playlists and your well wishes, I will cherish forever."

David M. Benett/Dave Benett/WireImage

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"Most of y'all met me when I was 15, and we have grown up together. You bring sooooo much joy into my life. I hope my art can continue to bring a little joy into yours," Beyoncé concluded in her ode.

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The singer signed her letter "I love you deep," repeating "deep" a total of 40 times. She also drew a bee.

In addition to the many birthday wishes from fans, the artist received messages from Tina Lawson, Jill Biden, Oprah, Taylor Swift, Missy Elliott and many more to mark her special day.