"I'm very blessed. I'm very happy," Vartan, 41, tells PEOPLE of his recent engagement to Lauren Skaar. The actor popped the question two weeks ago after a year of dating.
Vartan says he's not sure exactly when he knew Skaar, who works in real estate, was "the one," but he's absolutely certain now.
"I know that I know, and I'm sure that I'm sure," he says. "It's that thing people always say: 'When you know, you'll know.' I never really understood what that meant, and I do now."
He adds: "We've only known each other for a little more than a year, but I literally cannot imagine my life without her. It's crazy. It's wonderful."
That said, the couple's in no rush to the altar. How long before the big day? "Ten years," laughs Vartan. "No, I'm kidding. There's no rules. We'll play it by ear, but maybe a year. Enjoy the engagement, then see what happens."
Vartan, who previously starred in ABC's spy series Alias and currently appears in TNT's Hawthorne, hit the red carpet Saturday at the 24th annual Genesis Awards, honoring Hollywood's animal-friendly efforts, at the Beverly Hilton hotel.
He was pleased to report that his and Skaar's dogs – he had two, she had one – have been cohabitating harmoniously as well. "Smooth as silk," he chuckled. "It's very nice."