I think I'll sit this one out. I can get into trouble just opening my mouth, even if it's just to sip tea, or a pint or two.
John is a kind friend of mine, and I've known him to spend hours promoting our hobby, with children, at train shows; where the track was little more than a SMALL oval, with possibly, one or two sidings. The children, and even adults very much enjoyed John's presentation; and yes, the children did ask "What else does it do..?"
John would quickly let the child stop the train at one of those sidings, and teach the child to deliver the car to the industry. Thus, it educated the child, on the reason for a railway, and the children enjoyed it that much more.
There is value to find many different pleasures, within this very flexible hobby of OURS. Sharing one's passion for these different pleasures, is of great value, on this web page.
Thank you, everyone, for contributing all sorts of views on this subject.