ET spoke to the 'NCIS: Hawaii' star at Paramount+'s upfront event Wednesday.
"I was just driving here with my friend and agent, Logan, and we were talking about, 'Wow, I’m in my 40s, I have worked my whole life doing what I love, and now it's come to a place where it gets to be what I love in a place I love -- Hawaii, with the people I love," Lachey gushed. "My family moved there, doing other things, like, hosting other shows for Netflix, or being able to finally write the book that I wanted to write, and have the show -- it all just feels very surreal, but like, all the hard work has come to fruition."
While it's definitely a pinch-me moment for the host and actress, Lachey said she's just trying to live in the moment and "relish in it."
She continued, "I'm just really trying to live in the moment. I just recently saw, I think it was Tom Hanks who said -- he gave an analogy about how when you're on top of the world, you're on top of the world, but that also, it will pass, so, just take in the moment, live in the moment and just relish in it."
The latest spin-off of the NCIS franchise sees Lachey as Jane Tennant, NCIS' first female special agent in charge of NCIS Pearl Harbor. Together with her team of specialists, they balance duty to family and country while investigating high-stakes crimes involving military personnel, national security and the mysteries of the sun-drenched island paradise itself.
Taking on the role of Tennant is something Lachey previously told ET she felt very "comfortable and confident" doing.
"I feel very comfortable and confident. I think a lot of that is my age. Maybe 20 years ago, 10 years ago, I wouldn't have been able to be in this position," she told ET's Kevin Frazier in November. "But at 40, there's really some grounding force that happens to you, especially as a woman and a mother of three and a wife."
The show's season 1 finale is coming up, and while Lachey couldn't say much, she did have a message for her co-star, Noah Mills, who ET will be catching up with next week.
"Noah, charm their pants off," Lachey said. "Noah, you got this."
NCIS: Hawaii's season 1 finale airs at 10 p.m. ET/PT Monday on CBS.