Mariska Hargitay Celebrates 25 Years of Law & Order: SVU and Turning 60: 'This Powerful Woman Emerged' (Exclusive)

When Mariska Hargitay first got the role of NYPD detective Olivia Benson on Law & Order: Special Victims Unit 25 years ago, she says, “I was the second detective alongside Elliot Stabler [played by her costar Christopher Meloni.] He was the male lead and a little more experienced and I was trying to catch up.”

Just as her character rose through the ranks to become lieutenant then squad captain, so did Hargitay as she became the show’s lead — with the departure of Meloni in 2011. Says Hargitay in this week's PEOPLE cover story, “As I became more comfortable with the character, you saw this powerful woman emerge.”

“In a way it was a rebirth,” she continues, “and that was powerful and exciting and beautifully uncomfortable to reckon with one’s own power.”

With the return of Law & Order: SVU on Jan. 18 for its 25th season, Hargitay’s Olivia Benson becomes the longest-running character on a prime time drama series — and the show becomes the longest-running drama series in TV history.

“We’ve been on a parallel journey,” she says. “There’s a thing WWOBD, what would Olivia Benson do? The fans would always talk about it, and one day it hit me. I also have those moments where I’ve sort of slipped into her. If there’s a crisis, I just take over and lead like that. Being strong and fearless. It’s sort of this perfect feminist story.”

As for her 25 years on the show, she says, “I have two diametrically opposed answers. One is I can’t believe it’s been 25 years, a quarter of a century! And the other is, I can’t see it any other way. I can’t imagine the show ending, and can’t imagine not going on this journey with my cast, my crew. I have so much to look forward to. And I’m still growing. I like that you can be so many things at one time. It’s learning to give yourself permission to be all of yourself.”

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

“I lead with my heart,” she says. “It’s hard for me to witness other people’s pain. I’m like a laser. I don’t do small talk very well. So I connect with people.”

“The other thing is that I’m vulnerable,” she continues. “That’s my superpower. I’m somebody who understands you can be vulnerable and a badass at the same time.” 

“We’re all in this together so let’s raise each other up,” says Hargitay, who did just that.

Inspired by the many survivors who told her the show is the reason they reported their assault or abuse, she trained to become a rape crisis counselor and started the Joyful Heart Foundation in 2004 to focus on healing, education and advocacy.

“The number one thing that people can do is simply listen, not interrupt, not say, ‘I know how you feel,’ not say anything but to bear witness,” she says, sharing the wisdom that further deepened her role on the show and the deep connection she continues to share with her character. 

It’s something she’s grateful for as she not only marks the show’s 25th anniversary, but her upcoming 60th birthday this January 23 as well.

“I’m so proud of it and I’m grateful,” she says of entering her next decade. “I’m stronger than I’ve ever been.” 

For more on Mariska Hargitay, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here. 

Law & Order: SVU returns to NBC for its 25th season on Thursday, Jan. 18 at 9 p.m. ET.