“I take care of him. When he’s happy, I’m happy,” says Stella. Merle replies, “I’m happy when she’s around.” Merle and Stella have been married for 79 years. When Merle was recently admitted to a nursing home, he was miserable—so Stella gladly brought him home. He’s 101, and she’s 95. Though she needs a walker to get around, she lovingly does what she can for her husband, such as preparing the food he likes. But she couldn’t do it on her own. Grandchildren and neighbors help with the things Stella can’t manage.

Stella and Merle’s life together is an example of…