Admiral Yi Sun-shin of Joseon set an unprecedented record of 23 victories in 23 battles in naval history. Facing political frame-ups, torture, the death of his son, and an overwhelming enemy fleet, where did he draw the strength to maintain composure and precise strategy? He lit a lantern every single night and meticulously recorded the day’s weather, troop conditions, and his deepest sighs in Nanjung Ilgi. Writing a diary was not just a military report, but a self-healing ritual to clear away frustration and anxiety. Today, BuildSelf introduces the cognitive psychological effects and modern nightly journaling practice based on Admiral Yi’s ‘reflective diary’ routine.
Historical & Academic Evidence
This content is based on Yi Sun-shin's Nanjung Ilgi & Journal of Experimental Psychology.
1. The Emotional Catharsis & Amygdala Calming Effect of Expressive Writing
When faced with negative emotions such as extreme fear or frustration, the brain’s fear center, the Amygdala, becomes highly overheated. In this state, frontal lobe functions responsible for rational judgment and willpower are paralyzed. According to cognitive psychology studies, ‘Expressive Writing’, which structures these amorphous emotions by writing them down by hand, forcibly calms the abnormal activation of the amygdala. By labeling emotions and organizing them into objective facts, the brain perceives the uncontrollable situation within a controllable range, instantly freeing cognitive resources and exerting strong stress resilience.
2. 3-Step Practical Routine for Modern Professionals
Set Up Night Concentration Environment
Late at night when your daily work is completely finished, turn off your smartphone and computer monitor. Open a notebook quietly under dim light and sit at the desk.
Describe Core Events, Weather & Honest Emotions
Lightly record the detailed daily events and weather of the day, then write down honest emotional knots such as accumulated fatigue, anger, or anxiety without filtration in the notebook.
Deriving Controllable Variables & Letting Go of Burden
As you finish, clearly draw a line between 'things I cannot control' and 'one thing I can control immediately tomorrow', and conclude the diary letting go of the burden.
3. Do Not Conscious Other’s Evaluation, Write the Truth Only for Yourself
To fully enjoy the emotional purification effect of a reflective diary, you must not care about others' eyes at all. If you start checking or censoring sentences due to concern like 'what if someone reads my diary', the objectification mechanism that relaxes the amygdala will not work. Just as Admiral Yi Sun-shin expressed his fear, anger, and anxiety without addition or subtraction through his brush, you must be thoroughly honest with yourself in the most private writing space to finally relieve cognitive pressure.
📌 Frequently Asked Questions (FAQ)
What if I have nothing to write or don't have enough time every day? ▼
No need to write long. Just writing three lines is enough. Writing just 'one thing that exhausted me today', 'my emotion at that time', and 'one thing I can correct tomorrow' triggers the same emotional objectification mechanism in the brain.
Is the effect the same when writing on a smartphone diary app or typing? ▼
In principle, writing by hand with a pen on paper is most effective. The tactile feedback of transmitting fine sensory information from hands and arms to the brain awakens the frontal lobe's cognitive control more clearly. However, even when typing, you can sufficiently experience the emotional control effect if you maintain focus with device notifications blocked and describe honestly.
