“I want to write a book, but I don’t know where to start.”

I’ve seen hundreds of comments like this on writers’ forums. Basically, it means, “I want to write a book, but it’s a lot of work and books are long and I already feel too overwhelmed to do anything.”

Understandable. Writing a book is hard. Long-term goals are hard for a lot of people. They’re not really sure how to stack up a series of short-term goals to get to their end goal of writing a book.

If that’s you – think of writing a book as something similar to running a marathon. That’s running, with your own body and nothing else, a little over 26 miles all in one go. Running a marathon is also hard. But people, many of them just for fun, run them all the time.

You can’t wake up one morning, decide you want to run a marathon and then run a marathon the following day. It’s not possible. However, you can get up the next day and run two miles. And then in a few days, three or four. Eventually, you might be able to run 10 miles at a time. Fifteen. Twenty.

Marathon runners work their way up to running 26.2 miles. They train for months in advance. They have setbacks. Even during the actual race, sometimes they have to walk for a little while. They struggle. They can do a lot of things to try and prevent injuries and setbacks, but there’s no guarantee they won’t happen. They push themselves as far as they can go, and then some. Many make it to the finish line. Many never do.

To write a book, you can plan and worry and ask a dozen questions of people more experienced than you are, but if you never actually start writing, there’s no chance you’re going to write a whole book from start to finish, from beginning to end.

Start. Start slow. Start small. You don’t write a whole book at once. You write it line by line, chapter by chapter. Finishing a book – that is your finish line. Writing the book itself may not be a race, but it’s still a long and exhausting process. You can’t give up before you even begin.

Maybe you will never write a book, the same way you may never run a marathon. But a runner can run a dozen 5Ks, 10Ks, half marathons – as a writer can write articles and short stories and novellas.

Maybe you will write one book, run one marathon, and realize the extreme just isn’t for you. That doesn’t mean you have to quit doing what you enjoy. It just means you can do it in smaller bursts. There’s still value in that. There’s no value in giving up completely just because a writing a book is very long and time-consuming and hard.

This is not an easy thing to do. But it can be done. Now go – go write. Go do something. One step closer to finishing. Small – but essential.

Meg is the creator of Novelty Revisions, dedicated to helping writers put their ideas into words. She is a freelance writer and a nine-time NaNoWriMo winner with work published in Teen Ink, Success Story, Lifehack and USA TODAY College. Follow Meg on Twitter for tweets about writing, food and nerdy things.