Singer Lee Chan-won revealed an anecdote about his efforts to correct his dialect. In episode 49 of KBS 2TV's "The Secret of Celebrity Soldiers," the terrible reality of dementia and the stories of various people overcoming it are covered. This episode focuses on the dementia battles of genius actor Robin Williams, action star Bruce Willis, and former U.S. President Ronald Reagan, who made the world laugh.

Robin Williams is famous for the films "Dead Poets Society" and "Good Will Hunting." He suddenly passed away in 2014, which sparked various conspiracy theories such as the "Illuminati involvement theory." In the months before his death, he suffered from abdominal pain and constipation, frequently made line mistakes, and showed severe anxiety symptoms. Every dawn, he obsessively asked the director, "Was my acting okay?" An autopsy after his death revealed that his brain was filled with dementia-causing substances, identified as early signs of a "fatal rare dementia" that spread to the brain through the "gut-brain axis."

Bruce Willis is an action star well known for the "Die Hard" series. In the three years before his retirement, he filmed 25 movies but endured the humiliation of receiving the "Worst Actor Award." It was revealed that he was suffering from "frontotemporal dementia." His reliance on an earpiece during filming shocked the cast members.

Lee Chan-won empathized with Bruce Willis's past story and mentioned his own experience of holding a pen in his mouth to correct his Daegu dialect. Lee Chan-won's remarks became an opportunity to share the difficulties of correcting language habits. Additionally, Jang Do-yeon caused laughter by mistakenly mentioning a representative work of Bruce Willis's ex-wife Demi Moore. She said, "This is all because of Chan-won," lightening the mood.

Former President Ronald Reagan confessed to battling Alzheimer's dementia in 1994, four years after his retirement. His wife, Nancy, described Reagan's battle as a "long farewell." Although Reagan did not recognize his wife, he always smiled brightly whenever she appeared. Lee Hyun-yi was moved to tears by Reagan's love, saying, "Even if memories are lost, emotions remain."

Professor Muk In-hee, an authority on brain aging research, warned on the show, "The seeds of dementia grow from your 40s." The cast members each exclaimed, "That's me!" expressing their surprise. The broadcast airs on March 24 at 8:30 PM and can be watched later on Wavve.