Review and Resurface

A note you write once and never see again provides almost no long-term value. The final stage of a PKM system is bringing notes back into view at the right time – not just when you search for them, but on a schedule that keeps ideas alive in your thinking.

The Forgetting Curve

Hermann Ebbinghaus demonstrated in the 19th century that memory decays predictably over time. Without any review, most of the details of something you learned are gone within a week. But each time you review and recall information, the forgetting curve resets – and the interval before the next decay gets longer.

This is the principle behind spaced repetition: review information at increasing intervals to retain it with minimal effort. Review too soon and you waste time on things you already remember. Review too late and you have forgotten too much.

How This Applies to Notes

Most PKM systems are designed for retrieval – you search when you need something. Spaced repetition adds a different mode: proactive resurfacing. Your system surfaces notes on a schedule, even when you are not actively looking for them.

This matters because the best time to connect an old idea to a new one is not always when you are searching. It is often when you encounter something new and are prompted to remember something relevant.

Practical ways to resurface notes:

• A daily or weekly "random note" habit – open one old note at random and spend two minutes with it;
• A dedicated review queue – notes tagged #to-review get revisited on a schedule;
• Tools with built-in spaced repetition – Readwise resurfaces highlights from books and articles on a schedule;
• The weekly review – a regular session where you scan recent notes and look for connections.

The Weekly Review

The weekly review is the most reliable resurfacing habit. Once a week – typically at the end of the workweek or on Sunday – you spend 20 to 30 minutes on your PKM system:

• Process anything remaining in your inbox;
• Scan notes from the past week;
• Look for connections you missed;
• Update your current projects;
• Identify anything worth revisiting next week.

The weekly review transforms your PKM system from a passive archive into an active thinking partner.

Resurfacing vs Searching

Searching is reactive – you go looking for something specific when you need it. Resurfacing is proactive – your system brings things to your attention that you did not know you needed.

Both are valuable. But most people only build for searching. Adding resurfacing – even as simple as one random note per day – meaningfully changes how much you get from your system over time.