Glen Campbell's music is part of the American soundtrack. His biggest hits, like "Rhinestone Cowboy" and "Wichita Lineman," plus countless others, have been heard by millions all over the world.
His guitar playing is so inventive, Frank Sinatra wanted him for his hit "Strangers in the Night," and so did the Beach Boys -- he was featured in their song "Fun, Fun, Fun."
"I have been blessed, I really have," Campbell said. "I really have, I figured it out that I'm not that bright, but God gave me a break."
Now, at 75, Campbell is struggling to remember that blessed life. He is fighting Alzheimer's. It is a battle he and all those who share this disease cannot win.
"I wasn't a big star," he said.
We disagreed, telling him, "You are a big star,"
"Well, it's still the same size," Campbell countered with a laugh. "That's, ah, what was I saying? I'm going to be right in the middle of a sentence, man -- and it just goes, pew."
Campbell and his wife of nearly 30 years, Kim Woollen, spoke with ABC News in their Malibu home for their first television interview since sharing the news that he had been diagnosed with Alzheimer's.
"I hadn't gotten it yet," Campbell said. "In fact, I don't even know where it came from."
"Yes, you've been diagnosed with Alzheimer's," Woollen said to her husband.
"What? I haven't felt it yet," Campbell said, laughing. "I've always been forgetful anyway. I'm only what, 78?"
"75," corrected Woollen.
"Oh, so I've got a couple more."
We suggested that Campbell's decision to embark on a new tour is not only unusual, it's brave, because so many people, facing such a hard diagnosis, would turn all their focus to their health.
"I don't know how brave it is," Campbell said.
Sometimes it's Campbell's wife who acts as his memory.
"I just take care of him, which is a big job," she said. "We'd been noticing short term memory loss for quite some time. You know, he repeats himself. Tells the same joke several times in a row."
"Well, yeah, it's funny," Campbell joked.
"He'll tell a joke, laugh at it and a few minutes later tell the same joke, laugh, and then we laugh at him because he's just enjoying it so much," Woollen said. "You just make the best of each day and try not to worry about tomorrow."
"Definitely take care of what's today and tomorrow's going to have what it has," Campbell said.
"There's a verse in the bible that says, 'If the man findeth a good wife he's found a good thing,' and I found a good thing, or she found me," he said. "Did you find me or did I find you?"
"I think we found each other," Woollen said.
"That's what we did," he said. "Amen."
Hard Childhood Leads to Hard Drinking
In the old days, Campbell was a hard-drinking lover of country, a child of Arkansas poverty.
"Oh I love to play the guitar and I love to sing," he said. "I found out real quick you know, looking at a mule in the rump and gathering corn and picking cotton...I figured out real quick that that was work. I wanted to do something that didn't have so much work attached to it."
Like many Alzheimer's patients, he can still remember the years gone by -- starting out as a teenager in the early 1950s.
"In Albuquerque, N.M., they had a noon-day roundup thing and I was playing on it. Oh boy I was high cotton," Campbell said. He starts singing: "riding down the trail to Albuquerque, saddle bags all filled with beans and jerky. Working for the circle bee the TV ranch for you and me, circle bee in Albuquerque."