Catherine Zeta-Jones shared what keeps her marriage with Michael Douglas strong through the years.

They have proven that true love can withstand the tests of time.

With a 25-year age gap, Zeta-Jones and Douglas are considered amongthe most successful age gap relationships.

Catherine Zeta-Jones and Michael Douglas

In an interview withWSJ Magazinein 2021, Zeta-Jones shared, “The constant is love and respect.

We’ve never, ever lost our sense of humor, and we enjoy each other’s company.”

Douglas also shared his fair share of effort in making their relationship work.

Catherine Zeta-Jones and Michael Douglas at the F1 Grand Prix of Monaco 202

For Catherine Zeta-Jones and Michael Douglas, it helps that they get to spend long periods of time together.

So we’ve had in our relationship huge amounts of time where we’ve been just us.

We lived on the island of Bermuda for 12 years bringing up our kids.

We respect each other’s space, and our humor is just long-lasting."

He wrote, “Happy Anniversary to my darling Catherine!

I love you so much.”

Both of them still wanted to work on things as neither party filed for divorce or legal separation.

The couple’s health and wellness might have impacted their marriage.

In 2010, Douglas was diagnosed with cancer.

He stated that Zeta-Jones showed an unparalleled level of strength during this time.

He overcame the illness in 2011.

However, it was this time that Zeta-Jones wasn’t doing well mentally.

She reportedly checked herself into a mental health facility to treat her bipolar II disorder.

Less than a year after their break, the couple got back together in April 2014.

In an interview withThe Telegraphin 2022, Zeta-Jones shared her thoughts on what they went through.

I’ve been waking up to Mike for nearly 25 years.

I love being married but it’s a crazy thing when you really think about it."