Lydia's challenge was so hard for me! I have loved books all my life and picking just one was impossible. I do remember being obsessed with a book called Spooky Tricks when I was young and I think it was the basis of my love of watching magic shows. I used this cute image that I got with a past HYCCT prize too.
(and I totally found a copy of that book online for 3 bucks so I'll probably own it again very soon. Ha!)