Here is a link to an interview with Sir Terry Pratchett in The Daily Telegraph, speaking movingly of his Alzheimer's diagnosis, but I especially loved his description of his childhood with the various science experiments and his discovery of the pleasures reading...
The Pratchetts were a happy but thrifty family whose idea of a holiday was a week in Lyme Regis with friends. Terry was a forensic sort of boy, fond of expeditioning and experiments.
“My father encouraged me to do all the Just William things. He was never so pleased as when I electrocuted him by setting up a little device in his shed to give him a shock when he opened the door.” Crystal sets, astronomy, science… if the boy had a legitimate passion, his parents encouraged it.
He came to reading late, through a chance encounter with The Wind in the Willows. It detonated a love of books “similar to Hiroshima” and his real education began thereafter at the Beaconsfield public library, where he “read like a mowing machine”.