The kids consider how to take a picture of what someone is dreaming in Joshua and his Gang. Chapter 6 The Dreamers Page 31 (freely accessible)
That was sixty years ago; it may well now be a reality.
The chronicler of Joshua wonders at what stage present day technology is at with regard to retrieving memory from the document of the mind and offering a person the chance to experience an episode again.
I can remember a solo train journey when I was five years old; the red shiny suitcase, kindly conductor, water from a tap in the wall and the pointy paper cup, the excitement of travelling to an aunt's and uncle's farm for a summer visit. What fun it would be to relive the details.