I guess there was a moment for all of us that got us interested in audio, electronics, science and so forth.   To kick things off, this was got me going.  In the UK during the 60's and 70's there was a series of educational books for children called the Ladybird books.  It eventually ran to hundreds of topics, but were written in very clear language and with superb illustrations.   It shows what an effect this had on me - I remember precisely the book - Magnets, Bulbs and Batteries.  And tha