Designing a Decision Journal

You remember your investment successes as the product of insight. You remember your failures as bad luck. Neither memory is accurate, and this selective recall makes it impossible to improve. A decision journal fixes this.

Why This Matters

Memory is reconstructive, not archival. When you recall a past investment decision, your brain does not replay what actually happened — it reconstructs a version that is coherent with your current self-image and with how the outcome actually turned out. This produces systematic hindsight bias: successful decisions are remembered as having been more reasoned and confident than they were; failed decisions are remembered as having been more ambiguous and unlucky. A decision journal creates an unalterable record of actual thinking at the moment of decision — the only defence against hindsight bias.