A genuinely tough question. Possibly an old paperback copy of The Water Babies. If for nothing other than the Irishwoman who preferred to walk alongside.

And Genesis' Nursery Cryme - but especially The Fountain of Salmacis, which as an eleven year old surrounded as I was by crappy early 80's pop, opened my eyes to the potential magic of music. If not Nursery Cryme, then The Lamb.

Wasn't Peter Gabriel a quite lovely looking yung man back then...