What matters most often resists being measured cleanly.

Measurement requires standardization, and the things that matter most are usually particular to a situation, a person, a relationship. Anything that measures cleanly has been simplified to fit the instrument, and the simplification is where the substance tends to go. Resistance to measurement is not a defect.

Be careful when a number starts standing in for something important. Ask what the number leaves out. Then keep tracking it if useful, without letting it become the thing itself.