[Nothing great or original here, except maybe the metaphor. It's supposed to be a simple teaching post.]
Zimbabwe is only the most extreme recent example of this general rule; the central bank threatened to grow extremely large, and this caused it to shrink extremely small. The Swiss National Bank is another recent example, at the opposite extreme. It grew very large, but slowed down its growth by threatening to grow even faster. Now it has stopped threatening to grow even faster, we will probably see its growth speed up.
(It's the same with interest rates. If a central bank wants lower interest rates, it must threaten to raise interest rates.)
This is very standard economics. It sounds paradoxical, but it isn't. Let me give you an example that has nothing to do with money: