Measurement is a cost, paid in the thing being measured

What this is

Fifty notes on tracking your own time, written for somebody deciding whether to bother rather than for somebody choosing a product.

No product names, no affiliate links, no sponsored content.

Four things that hold

Measurement is a cost. It is paid in the time being measured, and most personal systems collapse because the cost quietly exceeded the return.

Observing changes the thing observed. The first week is never representative. That is useful if you wanted behaviour change and distorting if you wanted a baseline.

The method has to match the question. The expensive method is not the best one; accuracy beyond what the decision needs is waste.

The useful form is a short investigation with an end date, repeated when there is a new question — not a permanent system running until the data stops being trustworthy.

Where to start

You want to know where the week goes: two weeks of sampling.

Your estimates are always wrong: the overrun factor.

Other people are taking your time: the evidence-based conversation.

You have tracked for months and nothing changed: the limits section.

What this is not

Not medical advice. Persistent problems with sleep, energy or mood are a reason to see a doctor rather than to collect more data.

It does not tell you how to track a colleague, how to prove a point about a partner, or how to make your figures look better to an employer. Those appear only in the notes explaining why they should not be done.