Because he's young at heart?  More than likely, he looks like he has a failing heart:

Joe Hardy, an 84-year-old who founded 84 Lumber, just married a woman who is 62 years his junior.

Kristin Georgi, a 22-year-old with a toddler, worked at a spa in Pennsylvania when she met her future husband, according to the The (Pittsburgh) Post-Gazette.

"I knew he liked younger women. I didn't know she liked older men," says Megan Cobert, a classmate of Georgi's who used to wait on Hardy when he ate at a local restaurant.

"To think of someone of my age with an 84-year-old, it just seems impossible," Cobert says. "It blows my mind. But if she loves him, I can't see any reason why it wouldn't work out."

The USA Today story includes a picture.  Here's what I think they're thinking based on the picture:

Him:  *Boing*  She's going to give me a heart attack during the honeymoon.

Her:  *Ugh*  I hope he has a heart attack during the honeymoon.

Not that I'm cynical or anything.