The hobby that Maddy discovered on her school vacation, is one in which her father and his father pursue, it is a sphere of activity involving trains; one which permit's them to remain children and continue to pursue their imagination's.
In the Book, Where Good Ideas Come From: The Natural History of Innovation, Steven Johnson said;
“Legendary innovators like Franklin, Snow, and Darwin all possess some common intellectual qualities—a certain quickness of mind, unbounded curiosity—but they also share one other defining attribute. They have a lot of hobbies.”
As your out there discovering new things, what counts is not what you do, but how you feel about yourself when your doing it...
See You Soon
The Head Fairy