Fermentation is controlled decay. You create the conditions — salt, temperature, time — and then you step back and let the microbes do their work. It requires a kind of trust that modern cooking, with its precise temperatures and instant results, has largely abandoned.
A jar of sauerkraut is a small ecosystem. Lactobacillus colonies rise and fall over weeks, each succession changing the acidity, the flavor, the texture. You cannot rush it. You can only wait, and taste, and wait again. The best fermenters I know have the patience of shepherds and the attention of watchmakers.
There is a metaphor here about creative work, but I will let it develop on its own.