"You can write about anything," she said, but really? Anything? There's an awful lot of anything in the world. How could anyone possibly write about that?
Take hedgehogs--please. I'm sure someone can write about hedgehogs, but that someone can't be me. I don't know diddly about hedgehogs, so how can I write about them? (Unless asserting my inability to write about hedgehogs qualifies as writing about them.)
The list of things I can't write about would have to include abacus, ailerons, anaconda, Antietam, Asperger's Syndrome, Angelina Jolie, and the Alps--and those are just the As. I can't write about Belgium, carborundum, deltoids, or (to skip a whole bunch of letters) shimmy-dampers. My son the pilot could tell you all about shimmy-dampers, but once I've told you that, I've told you everything I know about the topic.
"Go on," she said. "Just write. About anything."
But I can't! Writing about something is hard enough--now you want me to write about anything too? Harrumph to that. No one can write about anything. Someone can write about something--and at the moment, this someone can write about nothing.
"Anything," she said.
There: I've written about it. Satisfied?