Glen Campbell was diagnosed with Alzheimer's in 2011, but continued to tour for the next two years, until his health forced him to retire. The 78-year-old now lives in a residential care facility and is largely unaware of his surroundings, but as his wife Kim recalls, the country legend had a surprising reaction when he was first given the devastating diagnosis.

"It was terrifying," she admits. "I couldn't even say the word Alzheimer's. I referred to it as 'the A-word.' I hadn't really told Glen about the diagnosis yet because I was afraid to use that word.

"I had to finally use 'the A-word' with him, and he accepted it," she continues. "I was so fearful that he was going to just break down and be depressed and cry, and he was like, 'Really? Well I don't feel it.' I'm like, 'Well, good!'"

The musical legend may be suffering from dementia, but his wife says that his personality remains largely intact, including his sense of humor.

"It gets us through every day," she explains. "Even today, he tries to tell us a joke, and he has a real hard time communicating now: His sentences are made up of unrelated words, but he's trying to tell us a joke, and it doesn't make any sense to us, but he will laugh and laugh and laugh, and then we laugh at him, and then that makes him happy that he made us laugh. So we're still using humor to get through the tragedy of it all."

Campbell has always had a lighthearted approach to his disease, which has undoubtedly helped him, as well as his loved ones.

“I just take it as it comes,” he said in 2012. “I know that I have a problem with that, but it doesn't bother me. If you’re going to have it handed to you, you have got to take it anyway. So that is the way I look at it.”

The 'Rhinestone Cowboy' singer's family visits him as much as they can, determined to savor every day with the music legend.

“There’s a lot of sadness,” Campbell's wife says, “[but] we just continue to try to make the best of every day and keep a sense of humor.”

A documentary about Campbell's extraordinary life and career, 'Glen Campbell ... I'll Be Me,' won the prestigious Gibson Music City / Music City Films Grand Jury Prize when it premiered at the Nashville Film Festival last April. The film's soundtrack includes Campbell's final recorded song, 'I'm Not Gonna Miss You,' which received two Grammy nominations and an Oscar nod.

Download the 'Glen Campbell ... I'll Be Me' soundtrack here.