My grandpa didn't understand kids and was palpably not very interested in them, but made the effort for regular visits and was still capable on connecting with us about things that interested him, like canoeing and backyard birds and telling stories from his youth. We didn't see him as much as our other grandparents because he used his vacations to travel, but he was affectionate and kind enough that it was really fun and exciting to get to know him better as we got older.

And it's not like this is unique. It's an equation that isn't hard to pull off because tradition is there to help you. LW's mother was just selfish and didn't make the effort, and now she's experiencing the consequences.