Hugh Dancy is closing the case on this secret.

As the Law & Order star celebrates his 20th anniversary with wife Claire Danes, he reflected on what makes their marriage so strong.

“I picked right,” Dancy told E! News in an exclusive interview. “I could give you a lot. It would just sound cliché, but I mean, it’s all true: care and consideration, all the rest of it. Time takes on different meanings as you pass the big milestones in 5, 10 years.”

At the end of the day, he emphasized, “We’re just doing our best.”

But the 51-year-old—who met Danes in 2006 before tying the knot three years later—also knows what’s needed in a relationship is case by case.

“I don’t think there’s a single secret that you can pass on to anybody else,” he added. “You never know what’s the truth of somebody else’s relationship.”