Could be the book you loved the most, the series you daydreamed about, book that inspired you, fascinated you, your comfort read…anything.
And why.
I LOVED the Anne McCaffrey Pern books. I would walk around daydreaming about new adventures set in the books’ world. The Dragonsong books really connected my love of music with my love of fantasy (and animals).
Toss up between Herbert the Timid Dragon by Mercer Mayor and Ferdinand the Bull, by whoever its by. Both were formative for me and I remember them distinctly 40yr later