Key Takeaways
The subject in one line
- This playbook is about thinking better, learning faster, staying calm under pressure, and treating people well.
The simplest habits that matter most
- Speak through three filters: truth, need, and kindness.
- Calm the body first, then use one small frame: goal, constraint, next step.
- Build resilience by naming what is controllable and what is noise.
- Use empathy without surrendering boundaries: understand first, then set kind limits.
- Give feedback that targets behavior, impact, and a clear request, not identity.
- Turn fights into tests by asking what evidence would change a mind.
- Say “I do not know” early, then check, to protect trust and speed real learning.
- Think in probabilities, update with evidence, and score forecasts to stay honest.
- Learn for the long run with active recall, spaced repetition, interleaving, and deliberate practice.
- Train attention with environment design, not willpower.
- Keep money and friendships strong with small, repeatable systems.
Story & Details
What this is about
In January two thousand twenty-six, a compact set of lessons sits in plain view: calm first, clarity next, kindness always. The goal is not to sound smart. The goal is to stay accurate, steady, and fair when it counts.
Three filters for speaking with integrity
Integrity starts before the mouth opens. A sentence can pass three quiet checks. Is it true. Is it needed. Can it be said with care. If it is not true, it does not belong. If it is true but not needed, it can wait. If it is needed, it can still be delivered with kindness. This keeps honesty without cruelty.
Calm first, then thinking
Under pressure, the body can run the show. A minute of slow breathing lowers arousal and buys mental space. After that, one short frame can stop a spiral: name the goal, name the constraint, choose the next step. Small words, big effect.
Resilience means separating control from noise
A hard day feels lighter when control is made visible. One part is controllable: the next action, the next message, the next five minutes. One part is not: other people’s moods, the past, and random timing. Naming the split reduces helplessness and makes the next step clearer.
Empathy that does not surrender boundaries
Empathy is not agreement. A strong move is to restate the other person’s view so well that he says it is fair. Only then does a reply land. Boundaries keep empathy clean. Help works best when the benefit is high and the personal cost is low or moderate, with a clear stop point. Kindness without limits becomes resentment.
Criticism that changes behavior, not identity
Feedback can be sharp without being personal. A clean pattern is behavior, impact, request. It avoids labels. It points to a concrete change. It protects the relationship because it does not attack the person.
The fastest way to reduce conflict in arguments
Many arguments are not about truth. They are about status. One question cuts through the fog: what evidence would change the mind. This turns a fight into a test. If evidence can move the view, a path exists. If not, energy can be saved.
“I do not know” is a skill, not a failure
A sharp mind says “I do not know” early. Then it checks. This prevents confident mistakes, protects trust, and saves time. It is also the start of scientific thinking in daily life.
Probability thinking: beliefs are not binary
Many beliefs are not simply true or false. They are more or less likely. A simple habit is to attach a rough percent to a claim. New evidence should move the percent. This lowers ego and makes learning visible.
The Brier score: a simple way to judge probability predictions
A forecast is not only about being right. It is about being calibrated. The Brier score is one way to score probability forecasts, using squared error. It punishes high confidence when wrong more than low confidence when wrong. That is a practical teacher: humility plus accuracy.
Bayes’ rule: updating without drama
Bayes’ rule is a formal way to update a belief when new data appears. It forces respect for base rates. A common trap is to ignore the base rate and overreact to a vivid story. A steadier move starts with how common an event is, then updates with the evidence.
Planning fallacy: the inside view lies by default
The inside view imagines steps and obstacles. It feels realistic, and it is often too optimistic. The outside view looks at similar past tasks, uses typical outcomes, then adjusts. A tempting shortcut is to average a best-case and worst-case guess. Real data beats vibes.
P-values: one number is not a decision
A p-value can show how incompatible data is with a chosen model, but it does not measure truth. It does not measure impact. It is easy to misuse as a gate. Good decisions also need effect size, uncertainty, and context.
P-hacking: how “good results” can be manufactured
P-hacking happens when many hidden choices are tried until a small p-value appears. The result can look clean but be fragile. Better protection includes transparency, preregistration, and a focus on estimation over threshold worship.
A/B tests: significant can still be tiny
A small change can look statistically significant with a huge sample. That does not mean it is worth shipping. A steady checklist is simple: how big is the effect, how uncertain is it, what does it cost, and what could break if it rolls out.
Learning that lasts: retrieval beats rereading
Rereading feels smooth, so it feels effective. Retrieval practice feels harder, so it feels worse. But pulling information from memory builds stronger long-term recall. Low-stakes quizzes with quick feedback are a reliable way to learn.
Spaced repetition: timing matters more than effort
Spaced practice spreads study over time. This is often stronger than cramming. As the final test gets farther away, the best spacing between reviews also tends to grow. This is a simple way to plan study without guessing.
Interleaving: mix problems to learn the choice of method
Blocked practice repeats one type of problem at a time. It can inflate confidence because the method is obvious. Interleaving mixes types. It forces method selection, not only method execution. That improves transfer.
Deliberate practice: the “slightly hard” zone
Growth needs work that is not too easy and not impossible. The practice targets weak points, includes feedback, and stays slightly hard. Comfort practice feels good but changes little.
Attention is trained by environment, not willpower
The easiest win is to change friction. Make good actions easy. Make bad actions harder. Turn off alerts. Set fixed windows for news. When the urge to react hits, write a private draft, add a short evidence check, then wait. This breaks doomscrolling and impulse posting.
Small systems for money and friendship
Money gets calmer when rules are automatic. Save first when money arrives. Use a weekly spending limit that requires little thinking. Wait two days before big buys. Review once a month.
Friendships stay alive with small, specific contact. One short message each week with one detail and one clear question beats vague reactions.
A tiny Dutch mini-lesson for daily life
Dutch is the language of the Netherlands (Europe). Two short sentences can carry a calm, useful tone.
Ik begrijp het.
Plain meaning: this is used to show understanding without drama.
Word-by-word: Ik means I. Begrijp means understand. Het means it.
Register and use: neutral and common, suitable in everyday talk and at work. A shorter informal variant is: Snap ik.
Dat klopt.
Plain meaning: this is used to agree with a fact in a calm way.
Word-by-word: Dat means that. Klopt means is correct.
Register and use: steady and simple, useful for agreement without extra emotion.
Conclusions
A quiet ending
By January two thousand twenty-six, the pattern is clear: better thinking is built from small choices made well. Calm the body, speak with integrity, update beliefs with evidence, and learn in ways that last. The result is practical: clearer decisions, steadier emotion, kinder relationships, and less wasted effort.
Selected References
Public links for deeper study
[1] https://www.whz.de/fileadmin/lehre/hochschuldidaktik/docs/dunloskiimprovingstudentlearning.pdf
[2] https://augmentingcognition.com/assets/Cepeda2006.pdf
[3] https://pdf.retrievalpractice.org/guide/Roediger_Agarwal_etal_2011_JEPA.pdf
[4] https://files.eric.ed.gov/fulltext/ED557355.pdf
[5] https://www.amstat.org/asa/files/pdfs/p-valuestatement.pdf
[6] https://dmg5c1valy4me.cloudfront.net/wp-content/uploads/2020/09/08145800/simmons-nelson-simonsohn-false_positive_statistics-psycholsci2011.pdf
[7] https://help.osf.io/article/330-welcome-to-registrations
[8] https://www.gary-klein.com/premortem
[9] https://www.cbrfc.noaa.gov/papers/espvs.primer.pdf
[10] https://ocw.mit.edu/courses/res-6-012-introduction-to-probability-spring-2018/resources/bayes-rule/
[11] https://d-nb.info/1151585556/34
[12] https://youtu.be/kz2tvO_ZAKI
Appendix
Definitions
A/B test. A simple experiment that compares version A and version B under similar conditions to see which performs better.
Active recall. Learning by trying to pull information from memory instead of reading it again.
Base rate. How common something is before new evidence is added.
Bayes’ rule. A method for updating a belief when new evidence appears, starting from a base rate.
Boundary. A clear limit on what help is offered, how far it goes, and when it stops.
Brier score. A way to score probability forecasts using squared error, where wrong high-confidence forecasts are punished more.
Calibration. How well stated probabilities match real frequencies over time.
Confidence interval. A range of plausible values for an estimate, used to show uncertainty.
Deliberate practice. Practice that targets a weakness, stays slightly hard, and uses feedback to improve.
Doomscrolling. Long, repeated scrolling through negative or conflict-heavy content that raises stress and lowers useful learning.
Effect size. How big a change is in practical terms, not only whether it can be detected.
Empathy. Accurate understanding of another person’s view and feelings, without automatically agreeing.
Goal–constraint–next step. A short frame that names what matters, what limits exist, and the smallest useful action to take next.
Inside view. A planning style that focuses on imagined steps and obstacles in the current case, often leading to optimism.
Integrity filters. A quick check for truth, need, and kindness before speaking.
Interleaving. Mixing different kinds of problems during practice so the learner must choose the method, not just repeat it.
Outside view. A planning style that looks at outcomes from similar past cases and uses them as a starting point.
P-hacking. Trying many analysis choices until a small p-value appears, often without disclosing the hidden flexibility.
P-value. A measure of how incompatible the data is with a chosen model, not a direct measure of truth or importance.
Planning fallacy. The tendency to underestimate time, cost, and risk because the inside view ignores typical outcomes.
Pre-mortem. A planning tool that imagines a future failure and lists likely reasons, so risks can be found early.
Preregistration. Writing an analysis plan before looking at results, to reduce hidden flexibility.
Probability forecast. A prediction stated as a percent chance rather than a yes-or-no claim.
Reference class forecasting. An outside-view method that predicts by using outcomes from a group of similar past cases.
Retrieval practice. Strengthening memory by pulling information out of memory, often through testing.
Spaced repetition. Reviewing across time with gaps, which improves long-term recall compared with cramming.
Transfer. The ability to use learning in new situations, not only in the original practice setting.
My Diary - Leonardo Cardillo 