The day my dad retired, he brought back a cardboard box. An enamel mug, a fountain pen, a contact book, a photo at the entrance of his unit. He placed the box on the balcony and never opened it again.

In the first year, he sat on the sofa every day watching TV, from morning till night. My mom said, "Go out for a walk." He asked, "Where to?" My mom said, "Anywhere is fine." He didn't move.
In the second year, he started growing flowers. The balcony was filled with them, all green, no blooms. I asked, "Why not grow flowering plants?" He said, "They're hard to take care of."
In the third year, he started talking to me. Not about work or health, but about his flowers. Today, he watered them several times, and one leaf turned yellow. I listened. Hmm. Hmm. Hmm.
Last week, he called and said one pot of flowers was blooming. I asked what kind of flower. He said, "I don't know, I picked it up."
I went home for a visit. On the balcony, that flower with an unknown name was blooming perfectly. He stood nearby, hands behind his back.
When I was leaving, he saw me to the door and said, "Next time I come back, the flowers will still be blooming."
And you? Have you talked to your dad? Not just "Hmm" kind of talk.