"I think it's at what age you make that commitment," Theroux, who got married a few weeks shy of his 44th birthday, elaborates. "When you hear about people in the '50s getting married at 20, you're like, 'What were they thinking?'"
Theroux adds that his grandparents were together for over 50 years and shares their secret. "My grandfather used to write one sentence every day in his journal: 'I love Anne more than ever today,'" he says. "I think that was his meditation -- keeping him in his marriage, and also his appreciation for it. It was very touching."
Aniston and Theroux have only been married a little over a year, but he says there's already been lessons learned. "I think it taught me to settle a little bit," he explains. "It does have a calming effect."
That being said, Theroux does admit that being one-half of a celebrity couple does have its disadvantages. "It's a luxury problem, but I would love to walk around New York with my wife," he says. "Take her to Washington Square Park."
As for why he's never even tried to stroll through the park with Aniston, he quips, "It would turn into a sh** show. It would be not fun."
The couple did, however, attempt a shopping trip on Wednesday in NYC's Soho neighborhood, just days after he revealed to ET the secret to his happy marriage. "We appreciate each other's sense of humor, we respect one another and we get along," he shared. "I know it sounds simple but it's true!"
Also in ELLE, Theroux admits that the photos that went viral of him jogging in revealing sweatpants on set of The Leftovers in 2014 were "embarrassing" for him. "It's like having someone yank your shorts down in public. It doesn't feel great. Anyone who has an unflattering picture taken of them would probably say, 'Join the club,'" he says. "It has the appearance of a compliment, but it's more mortifying than anything else."