Tonight we're digging deeper on Alzheimer's, the most common cause of dementia.
About five million older Americans have it, including the husband of former Supreme Court Justice Sandra Day O'Connor.
Now she retired last year to care for him, and yesterday we got a surprising and moving glimpse into their life.
John O'Connor, who lives in an assisted living facility, has actually found a new romance with a fellow patient and his family is happy for him.
Turns out, this is more common than you might imagine.
Tonight, CNN's Gary Tuchman investigates.
Thomas Schnyder and Josephine Scalzo are both in advanced stages of Alzheimer's disease.
They live in an Alzheimer's group home in Las Vegas, and they like each other a lot.
We asked the owner of the group home about Thomas.
He kiss[es] everybody, you say good-bye and then, you know, he does... we try... he likes to be touched.
He likes to joke with other people. But he cannot even speak, you know.
So, Josephine is behind you. That's his girlfriend, right?
Oh! Josephine, right here, yeah.
But there's another woman in Thomas' life.
Well, hello. Hi.
His bride of 54 years, the woman who takes care of him, is devoted to him and still loves him.
Yeah, keeping him calm...
Her name is June, and she regularly visits her husband, who no longer knows who she is.
You see him with this other woman, and they're holding hands.
I mean, I would think, you know, it must be hard to see that. Is it hard?
In a way, but not totally, because I understand his condition, and if he can find someone to make him laugh or talk to, that's fine.
Because Alzheimer's affects one's judgment and memory,
finding someone else isn't the same as actually betraying or stepping out on your spouse, whom you know, who you remember and who you've made a commitment to.
Here's what I think -- that you're very generous, very unselfish, and isn't that what love's all about?
Oh, yes. Yes.
The Schnyders have had a good life and raised two healthy children,
but now Thomas has two ladies in his life.