Have you ever wanted something so badly that you would be willing to do anything for it? Even walk a “practice dog” that’s not a dog at all but a plastic orange juice jug with painted spots and an orange lid for a nose?

That’s what Zelly Fried does in Erica Perl’s book “When Life Gives You O.J.” Zelly is so desperate for a dog that she decides to go along with the strange plan of her crazy grandfather, Ace. He thinks if Zelly proves to her parents that she can take care of a practice dog, they will let her get a real dog. This means walking (really, dragging) the practice dog, feeding it (filling the jug with water and dog food) and even cleaning up after the dog (dumping out the contents of the jug and then picking it up; it actually sounds grosser than real dog poop!).

Zelly, who is 10 years old, must do all this without feeling like a total weirdo in her new Vermont town.

Perl never had a practice dog when she was a kid, but she did live in Vermont and she did want a dog.

A girl and her grandfather

“There’s a lot more of me in this book than anything I’ve written,” Perl says. “I started thinking about my grandfather and my relationship with my grandfather, and I realized that there was a story that I wanted to tell . . . it was about a girl and her grandfather,” she says, talking from her home in Washington, where she lives with her husband and kids, ages 8 and 11.

Author Erica Perl recommends that kids keep a messy journal — one with jokes, conversations, lists, doodles and even candy wrappers. (Sczerina Perot )

Perl was a lawyer in New York before she started writing children’s books, but she was always a reader. As a kid she loved “The Great Brain” books by John D. Fitzgerald, “Otherwise Known as Sheila the Great” by Judy Blume and books by Daniel Pinkwater and E.L. Konigsburg.

“People always said, ‘Write what you know,’ ” Perl says. “I had always been told that, but I always shied away from it because I felt like, ‘Well, what kind of story do I have to tell?’ ”

But when Perl started looking at her life differently, she realized that she did have a story to tell — just as everyone (even you!) does. To find it, Perl says, just take a step back and look at your life from a different angle.

“Think about how you would describe your friend to someone who had never met him,” she says. Pretend to be your friend, or draw a picture of him or her. This can give you ideas for a story.

The importance of being messy

Perl also advises young writers to read everything. KidsPost readers have heard that before. But what you may not have heard before is Perl’s second piece of advice: Keep a messy journal.

“When I was a kid, I always wanted to have a really neat journal,” Perl says. “And I never succeeded in that, so at some point I decided that my journal could be really messy.”

Perl says journals should include anything and everything: jokes, cool conversations, grocery lists, doodles, scraps of paper, ideas, candy wrappers.

“I have this rule that I attribute to my dog who passed away last summer,” Perl says. “Lucy was a dog that, if anything fell on the floor, she would eat it and then she would figure out later what it was. This is the inspiration for my journal rule: You always write it down, and you figure out later if it’s any good.”

Perl has kept hundreds of journals in her lifetime, and somewhere in them are the ideas that later became the books about Zelly and Ace.

What ideas would be in your journal?

— Moira E. McLaughlin