Nothing can rightly be called a first unless there is a second. First grade implies second grade; first class implies second class; first book implies (we hope) second book.
That is why first drafts are called first drafts. A writer must expect to write a second draft, a third even. No one can sit down and churn out countless pages of prose that don’t need rewriting. Jack Kerouac claimed he did it with On the Road, but we know now that he was stretching the truth.
The first draft is your opportunity to let all the words you have bottled up inside of you spill out onto the page. It can be as messy, as nasty, as melodramatic as you want. There are bound to be spelling errors, grammatical errors, factual errors, and missing information. The important part about a first draft is to write it all down.
Finishing a first draft is important because many of your anxieties about writing will vanish when it is done. You will know that you can in fact write things down. You know that your stories will live on in some fashion, as unruly as that first draft might be. You will have a tremendous sense of accomplishment. However, you are certain to feel some disappointment with the draft.
This is good. That disappointment will spur you on to a second draft. You might end up chucking aside the entire first draft and starting from scratch again. This time, your story will be clearer in your head. You’ll remember the good stuff, and happily leave out the dreadful. Or you might take the first draft and a fistful of sharp pencils and get to work pruning and primping. You’ll look up the right spellings, correct the grammar, fill in the missing information.
Just as important, you will read your work with a more critical eye. You’ll find places where you can expand your story and characters you can bring to life. You will start to notice themes in your work, and the way your story connects to something larger than yourself.
But without that first draft, you would not have gotten there. First drafts are meant to be tossed aside as some point. (Do you really think Herman Melville wrote, “Call me Ahab” the first time out? He probably wrote, “My name is John.” See what a second draft can do?) First drafts are your opportunity to write wildly, feverishly, frantically. Use this opportunity well.