Deaver was also around on Ronald Reagan's 84th birthday in 1995, when the world first caught a glimpse of Nancy's worst fears. The former president's memory had been slipping, and he became confused as he stepped up to the podium.
"It was horrifying to watch if you were sitting in the audience, because he was clearly not himself as he started off and was saying, you know, a word every two seconds or so," Deaver said.
"It was like he totally didn't know where he was. And then it was like, you know, the switch went on and" — Deaver snapped his fingers — "there he was again."
A Rose for His Love
It has been 10 years since Ronald Reagan was diagnosed with Alzheimer's, and Deaver says Nancy has devoted herself single-mindedly to his care.
"She just won't give up," he said. "He's there and there must be a part of him, I think she thinks, that knows and hears her."
And sometimes there have been those moments that hope is rewarded. Deaver recounted a time just a few years ago, when Reagan was out for a walk with one of his Secret Service agents.
Reagan stopped in front of a house surrounded by a picket fence and started to reach over to open the gate. Thinking Reagan was confused, the agent gently pulled Reagan's hand from the gate, Deaver said, and told him: "Mr. President, this is not our yard. We should go home."
But it turned out Reagan knew that wasn't his house, Deaver said. "And he said, 'Oh, I'm … I'm just trying to pick a rose for my love.' "