of course it is understandable.
My dad is also in his 50s. Some are surprised from his past to realize he recovered (personal history). I would also focus on an outstanding thing to remember, and make it valid, interview or what have you for ideas.
My father moved on to over 5 million miles as trucking, not a newb seeking "lot lizards and a joint", hes been an independent for 20 years or so, he even worked at a time when all trucking was absolutely horrible..starting in 1973. This evening I helped him with a chore on his rig. This past weekend, I saw a sign of alzheimers, he misinterpreted my age/abilities entirely. It is frightening. the past couple of years, sensing this, I have made several hours of video driving with him. I lost one parent when I was young, my mother, she gave me a heads up on my dads silent history. Communication, if not a hug, and keeping history of the stubborn old man is a great idea.
Odds are broken hearts have a seemingly endless abyss, staying stronger than this finds something incredibly special to cherish, no snapping defenses to dwell on, once it is known.