I used to write in my books. When did I stop? Why did I stop?
When I was quite small and could only manage crayons, I drew all over my books, inside and out, scribbly slashes of color.
My siblings and I always got books for birthdays and Christmases, and we were encouraged to use them. And use them we did — took them in the tub with us; read them in bed and dropped them over the side; splayed them out facedown to save our page, cracking the spine.
And we wrote in them.
Nobody ever told us it was wrong to write in a book (other than a library book, of course) — my father, an English professor, certainly wrote in his.
I scrawled on the endpapers and flyleaves, identifying the books as mine. In one of the "Little House" books, I wrote "This! Is! Laurie! Jo! Hertzel's! Book! Duluth, Minnesota, USA, the World, the Universe."
So mitts off, everyone else.
When I got a little older — 9 or 10, maybe — my parents gave me a package of bookplates. You wrote your name on one, licked the back like a stamp, and pasted it in the front of a book. The plates pictured a smiling green-and-blue cat and bore the words Ex Libris, which made me feel smart, because Ex Libris was Latin and I knew what it meant.