In many ways, this reflection seems to be the opposite of my note on not cramming:
Here, I wrote about not using every single idea in a given piece of writing. I still hold to that. What I'm talking about today is the shadow twin of that idea. In the creative hoarding mentality, I cling to my good idea, worried that I might not have another. In this scenario, rather than the writing being insufficient, every publication venue becomes suddenly not good enough. Even magazine or journals I've spent years admiring.
Both impulses, the impulse to cram a piece of writing full of every idea and the impulse to hoard and hold back good ideas come from a place of scarcity. On the one hand, the crammer fears never having the opportunity to write again. On the other hand, the hoarder fears never having a good idea again. In this second scenario, the writer becomes like Gollum with his "precious" in The Lord of the Rings. And look how that turned out.
Plus, there's this: when I have a new idea I think is good, I get very, very excited about it. I have lots of energy I want to devote to coaxing that ember into a bigger, brighter fire. But when I hold it back, thinking it would be a good book to write when I'm older, wiser, fancier, have more time, etc., that initial energy dissipates and the project tends to languish, never to be realized. Months or years later, when I come back to the idea, more often than not, the excitement has dissipated and even if I have the time, I don't care to pursue that particular line has thought.
The good news, though, is that thoughts are not a finite resource.
Spending a good one doesn't deplete one's creative accounts. Indeed, often thoughts beget more thoughts. Robert Boice's important book Advice for New Faculty Members (linked below) on successful faculty bears this out in its research on faculty productivity.