Mark and Dad are waiting for the train to get fixed, which is probably reason enough for them to take a walk outside, carrying their bags. Meanwhile, Mark seems fixated on the idea that he would not have learned more about his granddad from Dad while the train was actually moving. Perhaps Happy gets motion sickness or movement makes him forgetful.

Speaking of “trading stories”, would somebody remind me what story Mark traded with Happy about Granddad Forrest Trail? Was it the “Wow” remark or the “Sweet 70’s sideburns” comment?

Perhaps Mark might have learned more about his granddad if he had seen him once in a while as he grew up or had asked about him during the 18+ years he presumably lived at home with Dad (and Mom?). I suppose one thing I (as Mark) I would ask Happy is “How come Granddad looks more like a normal person than I do? Why do I look like a character on The Cartoon Network? And just who was my mother, anyway, Dad?”