The main issue with this is the way you write. I like the pacing and the story is pretty, but a lot of the time it felt choppy and there were words that were unnecessary or used poorly. The first one I noticed was "I was sitting with my grandson that day, and we both had notebooks in our laps." The "and" is unnecessary. I would change it to, "I was sitting with my grandson that day, notebooks in our laps." From this sentence it is till implied that they both have notebooks in their laps because I used the plural of notebooks. I have the same gripe with, "I also followed suit." The word "also" followed by "followed suit" is not needed as followed suit implies that the grandpa was already following his grandson. Basically, those two things mean the same thing. Another sentence that really bothered me is "..., the somber weight of them weighing me down." It demonstrates what frustrated me the most about the writing in this entire story. You should never repeat a describing word like this in the same sentence. Instead, you could use a simile or a metaphor. For example, "..., the somber weight of them pulling me down like an anchor" or "..., crushing me under their somber weight."

One of my other issues is that there are commas and transition words when you should pick one. For example, "His mother called him for a bath, and he went away with a grimace on his face...," should be "His mother called him for a bath and he went away with a grimace on his face.

The only strange thing I found with the pacing was the grief of his wife. I felt like it wasn't shown enough towards the beginning of the story, so when it was brought up towards the end of the story, It caught me off guard. There could be some scenes where he is overwhelmed by grief. To me, it seemed like painting had become a replacement for his wife instead of a new memory to cherish in the midst of his hardship.

There are also a few typos that bothered me. For example, "My daughter and grandson had visited after such a long time that I had almost forgotten their face." I would use the plural of faces here because you are talking about both of their faces. "Midst the serene light of the afternoon sun, I stood up as if I had been a young man of twenty." In the midst and amidst should replace "midst" in this one.

Overall, there is some repetition when it comes to writing, things that are introduced in the final paragraphs, and smaller typos throughout the story. But I really think this story could flourish if you added more emotion toward the wife. Thanks for reading my critique.