Kristen Bell didn't need a P.I. to find out what makes her and Dax Shepard's relationship work. 

The Veronica Mars alum revealed that when it comes to their 10-year marriage, it's their differences bring them closer together.

"I married my polar opposite," Kristen told E! News in an exclusive interview. "We are the antithesis of each other. We argue about absolutely everything, but there is a foundational trust that we've built that keeps us together and is quite stimulated by one another's opinions."

In fact, her and costar Adam Brody's new series Nobody Wants This, which premieres on Netflix Sept. 26, also delves into what it means when a relationship feels right despite the couple seeming to not make sense together.

As she put it, "I can definitely relate to being attracted to someone who is maybe on paper seemingly wrong for you." (For more with Kristen and Adam, tune into E! News Monday, Sept. 23 at 11 p.m.)

The way Kristen sees it, it's her and Dax's differing perspectives that push them out of their respective comfort zones.

"Being with someone who you are unlike or you don't have a ton of similarities with," she reflected, "it forces you to grow." 

In their 17-year relationship, they've grown into a united front, especially when it comes to parenting their daughters Lincoln, 11, and Delta, 9. For instance, since Kristen, 44, and Dax, 49, have committed to not lying to their kids, they've had to work together to develop accurate and appropriate answers.

"It requires a lot of brain power," the Good Place star told E! News in June, "because you have to filter what's appropriate for their age group, what isn't going to scare them too much, but just maybe enough. You have to make all these quick calls, all these blank decisions, and it's hard."  

It would be much easier for them to use the old-school "Because I said so" as reasoning, but Kristen noted that it doesn't "yield the best results." 

However, sometimes, finding an answer can be especially difficult when the question is morbid.

“When my daughter first asked us, 'What happens when we die?'" she reflected of Lincoln’s inquiry as a toddler. "My husband and I looked at each other and we were like, 'What tale do we choose?' And then we were like, 'We don't know. You might just become flowers, but you might end.'" 

Ultimately, the reasoning was sufficient for their little one.

"She cried for a minute," Kristen explained. "Then she went, 'Okay.' I still can't believe we got through that."

-Reporting by Marcus Mulick