Donald Maas says you should write what you know. Natalie Goldberg doesn't think it's a good idea to write what you know. Donald admits that the writing what you know has a tendency to produce unexciting protagonists, settings that can put you to sleep, and plot lines nobody wants to read. Natalie suggests that we think about how little we know before concluding we should know what we write. Her point is that writing what you know severely limits the field of what you can write. Furthermore, she maintains the reason we have imaginations is in order to write what we don't know.
Donald maintains writing what you know doesn't mean you have to record everything that is plain and usual. A person should draw upon their experience in order to make the story personal, passionate, and true.
This debate of writing what you know versus not writing what you know comes up relative to me in writing about Alejandro. I really don't know about Alejandro, per se. I was never an undocumented immigrant, I don't know Spanish, I was never a thespian. On the other hand, I have an imagination, and I read of a girl going through the dust bowl during the depression in Oklahoma who I thought was in a situation that presented enough of an analog to what an undocumented immigrant boy like Alejandro might experience. Maybe that's cheating. I don't know. Anyway, that was the way I was going about it.
Donald says writing what you know means writing what you see differently, what you feel profoundly and know that it's important for the rest of us to understand. He maintains none of us need to have lived a life of merit or through a newsworthy phase, of sorts. We only need our own unique outlook and the will to write with a new purpose. Natalie says to lose control when you write. To write such things as what you're not thinking of it and what you don't remember. She contends if you get out of your box and do some exploration of a new place you will be able to find the hidden, the extravagant, and the mysterious life of a wild mind.