Picture a popcorn maker.
A big one, like at the movies.
You feed in kernels, salt, and oil, and in a few minutes it begins overflowing with savory buttery goodness. Golden fluffs of transcendent flavor.

When I worked at the movie theater, we’d make bonus batches — a batch with double the salt and oil. Absolute heaven. Probably shaved a few weeks off our lives with every bucket, but we were seventeen, what did we care?
Anyway, I figure a writer’s brain is like that. The hopper spins round and round churning out the ideas at a ridiculous rate, the fluffy poofed tidbits spilling out in a cascade. Except instead of the lovely glass enclosure, the writer’s brain is a popcorn popper spinning over a great black void that swallows up all the sun-kissed salty bits. (1. I’m really hungry and would eat a whole bucket of popcorn with great vengeance right now. 2. Sun-kissed salty bits sounds dirty, upon further review.)
Most of those ideas go right down the memory hole.
Doing a little bit of daily writing, I figure, is a way to put the hopper in its glass case, at least for a few minutes; this is the benefit, I think, to doing a bit of unscripted, unpurposed writing every day. You get a time capsule, almost, of whatever you were thinking on a given day. More than once I’ve had the thought that “oh yeah, I wrote something about that in my Drivel this morning, let me go back and read it.”
My problem is, my handwriting is atrocious, so my lovely glass case is smeared and scratched and probably not worth looking into.
I dunno, I thought there was a metaphor in there somewhere, but all this post did was make me even hungrier.