What do about me refusing to go for a walk with my grandmother? I'm just not in the mood for it.
Why don't you go for a walk with her?
The truth is that I'm not interested in the old people's stuff around this place.
Even if you don't want to, it's good to spend time with your grandmother. Your grandmother will be lonely if you don't spend time with her.
Why do I need to participate in her life and concerns when they're not anything I'm interested in?
It's disrespectful to dismiss your grandmother because you're not interested. She's linked to a reservoir of history encompassing decades before you were born; you could learn a lot about life by listening to her.