I don't know what brought it to mind, but today I remembered going to a local swap meet when I was about 10 years old and finding an old journal at an antiques stand. Just a thin paperback, yellowed with age.
I breathlessly separated the pages, expecting treasure maps or something--but instead, someone had used it to record their shopping lists and how much they'd paid for the items in 1908. I could actually know how much things cost over a hundred years ago!!!
My eyes got really big, and I counted up the change in my purse as I took it to the seller. She turned the journal over in her hands, and looked at me with a funny expression. "You know this--this is really old, right?"
"I know!" I said. "It's full of time travel!"
In the intervening years, it got lost in one of a dozen moves (I wish I was exaggerating) and I've always wondered if some other child acquired that magical journal. It was one of the things that set me on my path to writerhood, so maybe it was magic!