Why does recency bias fail?

The most common reason recency bias fails: You read this lesson and intellectually agree that recency bias exists, then open your portfolio after a red week and feel the urge to sell. The bias does not operate at the level of intellectual agreement. It operates at the level of felt normalcy — what your nervous system treats as the baseline. Recognizing the concept without building a structural countermeasure changes nothing.

The fix: Pick a domain where you recently changed your mind or shifted your behavior — investment allocation, a judgment about a colleague, a habit you dropped. Write down the event that triggered the shift. Now write down the full history: the last 12 months, 3 years, or whatever the relevant window is. Ask yourself: does the recent event justify the weight I gave it, or did I let the last data point rewrite my entire model?

The underlying principle is straightforward: Recent events disproportionately influence your perception of what is normal or likely.