On International Women's Day, Gwen Stefani opened up about finding her voice and confidence during iHeartRadio's SeeHer Hear Her: Celebrating Women in Music broadcast. Stefani looked back on her decades-long career and shared the wisdom she's learned along the way.

Stefani first found her voice while performing in a high school talent show with some friends. The group had so much fun, they decided to form a band with Stefani as the lead singer. The band, of course, was No Doubt. Not only did this experience lead Stefani to finding her singing voice, but it also lead her to her most authentic voice—her songwriting. While her brother was the group's first songwriter, Stefani took over when her brother left. "I started writing songs. I didn't even know that I could," she said. "Nobody taught me. I don't know where they came from. It wasn't until I realized I had this gift to write my feelings out that I started feeling empowered."

During the special event, Stefani brought up one of her most famous and timeless tracks from that era of her career—"Just A Girl," which she wrote and performed for No Doubt. She said "something changed" when she performed the song live at that time, recalling how even when people didn't know all the words, they still related to the powerful message behind the lyrics. "I never thought I'd have an impact on anyone, let alone another girl would look at me with that energy" of "being on the same team" as them.

The empowering song cast Stefani as a girl power icon, however, she says that wasn't the goal when she wrote the lyrics. "I wasn't trying to be a role model. I wasn't trying to [have] a female empowerment song, I was simply stating the truth of what I felt and just being me," she explained.

Stefani did set out to be a boss, however, when she launched her own clothing lines later in her career. "We all play different roles throughout our lives. I'm not only going to give you the music, I'm going to give you the visual," she said. She described these business moves as showing off "another side" of her personality.

There's no denying Stefani's career has been super successful. For Stefani, though, she measures her success by the amount of creative freedom she has at any given time. She considers the most creative time of her life to be after No Doubt released their Rock Steady album. "I've never done things just to make money," she said. "That is my definition of success."

Stefani also shared what she's learned about beauty and confidence over the years. "There's nothing like being honest and real and authentic," she said. "That's beautiful and it's also brave."

When it comes to confidence, even Stefani struggles to feel her best all the time. "Confidence is pretty much everything for a performer," she says. "The confidence I have in my songwriting is in and out. It's hard. It's hard to keep that afloat. Being on stage if you don't have confidence—I have to do everything to make sure I have that confidence."

Ultimately, Stefani wants the world to know her as a songwriter above everything else. "That's the one thing that gives me that identity or that feeling that I'm actually using my purpose in the world," she said.