Write what you know. Or don't.

Everyone says "Write what you know." And I think that's a little absurd to take at face value. A story can start moving in a character, an idea, a motif--long before I know all the surrounding facts in excruciating detail. 

I am not a police officer. I have written characters who are. 

I am not a father. I have written fathers.

I am not a vampire spawned in the first century A.D. You get the point. 

Please don't handicap yourself by sticking only to what you know. Yes, you should taste-test all your ingredients to see if they pass believability. And if you don't know something, learn about it. Just a bit. 

But not too much! 

I paused to look carefully at the legal implications of state secession, and I'm still writing a book years later. Too far into the weeds, and you'll lose the momentum required to get the job done. 

Honestly, you need the sheer balls, the audacity, to write something you don't "know" about. Editing is where the rest gets sorted out.