A heartbreaking video is going viral this week showing the moment an elderly U.S. Army veteran with dementia does not remember the name of his own son.

Kenneth Keene Sr. is a 70 year-old veteran from Philadelphia who was diagnosed with dementia back in 2014, and the disease has since progressed to the point where he does not recognize his own son. His son Kenneth Jr. recently filmed a conversation he had with his dad in the car, and his father repeatedly calls him “John” when asked what his name is.

The video is part of a series of videos Kenneth Jr. has been making about his dad’s illness called “The Journey with ToughKenaMan.”

The video opens with Kenneth Sr. saying to his son, “do you know who I am?” to which his son responds, “you’re ToughKenaMan.”

“I’m Kenneth Keene and I’m tough KenaMan,” the veteran says. When Kenneth Jr. then asks if he knows who he is, his dad laughs before saying, “I don’t know exactly but I can see ya, I know ya.”

“Yeah? Who am I?” Kenneth Jr. asked, to which his father says he does not know before guessing, “John.”

“No, I’m not John,” Kenneth Jr. responds, then asking his father who he is again. Kenneth Sr. just laughs in response and keeps saying that his name is “John.”

Finally, when Kenneth Jr. asks, “Who is John?” his father replies, “I’m Kenneth Keene and you are Kenneth Keene.”

Kenneth wrote in the video description that his entire YouTube channel is his “effort to raise awareness and share real life experiences with the world while his father, U.S. Army veteran Kenneth Keene Sr. enters deeper into the many different stages of Frontotemporal lobe dementia.”

Watch the heartbreaking moment for yourself in the video below.