Observation is inherently noisy.

There's all kinds of details that don't matter--that average out to mush--that you can safely ignore.

But deciding which details matter and which can be ignored is an act of judgment.

It requires having a mental model of what you expect, so you can see the things that don't fit the model (and are thus important to attend to).

This is one reason why observing the whole system from afar is not viable; when you're up close you can sort through the signal, and then flag anomalies up the chain.

But when you're looking at all of it at once, you're drowning in a cacophony of signal.

If you don't have a mental model for what you expect to see in the signal, it's all just noise.