# How to make better decisions when you keep making the same kind of bad call - URL: https://www.agentskillpacks.com/guides/how-to-make-better-decisions - Updated: 2026-10-21 - Book: Mental Models That Actually Work by Ada Fenwick (https://www.agentskillpacks.com/books/mental-models-that-actually-work) ## Short answer To make better decisions, start with two questions before any big list of tools. First, can you undo this if it goes wrong? That tells you how much care the choice deserves. Second, what are one to three real reasons you might be wrong? Asking for the case against yourself is one of the best-tested habits in decision research. Then write the choice down with how sure you are, as a percent, and check it later. The written record is how you learn, because memory edits itself after the outcome. ## You decided fast, and it went the same way as last time You said yes to the project. Or the hire. Or the move. It felt right. You had good reasons. Six months later it went wrong in a way that looks a lot like the last one. And the thing that stings is this. You had a small doubt at the time. You just did not write it down. Now you search "how to make better decisions" and get a wall of quotes. Think like a billionaire. Use these 50 mental models. Most come with a famous name and no source. ## Why "just be objective" does not change anything The usual advice is to slow down, stay calm and be fair to both sides. It sounds wise. It barely works. In a 1984 study, one group was told to be as fair and unbiased as possible. Another group was asked to consider the opposite answer and how it could be true. The second group did better. Telling people to be objective did little, perhaps because most of us already think we are. The other usual advice is to collect more tools. But a long list of models does not help when a real choice lands on your desk. You need to know which one to reach for, and how much it can hold. ## Two questions that cover most of the ground We like how the book handles this. Its Decision Selector matches common situations to tools. And when nothing fits, it says to start with just two questions. The first is: can you undo this? Jeff Bezos called hard-to-undo choices one-way doors in his [2015 letter to shareholders](https://www.sec.gov/Archives/edgar/data/1018724/000119312516530910/d168744dex991.htm). Choices you can walk back are two-way doors. A two-way door gets a quick call and a deadline. A one-way door gets real time. The second is: why might you be wrong? Write the choice in one line. Write how sure you are, as a percent. Then write one specific reason the opposite could be true. Add a second or third only if it comes easily. That limit matters. In a [2002 study](https://doi.org/10.1037/0278-7393.28.3.497), people who listed two other ways things could have gone lost their bias. People pushed to list ten got more sure of themselves, not less. So stop at three. Then write your confidence again. If it moved, you learned something before it cost you. ## Write it down before you know how it ends The last step is the one people skip. Keep one notebook just for decisions. For each real choice, note what you decided, what you expect, how sure you are and what would change your mind. Weeks later, come back and write what happened. This is where the learning lives. Memory is kind to its owner. With a record, you can see where you run too sure and which tools you skip. A 2004 review of [95 studies on hindsight bias](https://doi.org/10.1207/s15324834basp2602&3_1) found the same pull again and again. People remember their old guesses as closer to what really happened. A dated note is the plain fix. Our page on [keeping a decision journal](/guides/how-to-keep-a-decision-journal) walks through the fields. ## Learn from past choices without blaming the outcome Most advice says learn from your mistakes. The catch is that a bad outcome is not always a bad decision. When things turn out well, people rate the very same decision as better and the person as more able. Baron and Hershey showed this in 1988, and a 2023 replication with 692 people found an even bigger effect. The book's card for this is called Judge the Decision, Not the Outcome. It takes about 15 minutes and carries a PROMISING badge. 1. Write the outcome in one line, then cover it with your hand or fold the page. 2. List what you knew, or could fairly have found out, at the time. Leave out what you learned later. 3. Grade your process from 1 to 5 on three questions. Did you have the key facts? Did you weigh real other options? Did you weigh the risks you knew about? 4. Now uncover the outcome and grade it from 1 to 5 on its own. 5. Put the choice in one of four boxes: good decision and good outcome, good decision and bad outcome, bad decision and good outcome, or bad decision and bad outcome. 6. Write one lesson. The most useful box is the bad decision with a good outcome. That is where you got lucky, and where the lesson is the one you would most like to skip. ## Asking other people, the right way Asking people you trust is common advice, and it helps more when you ask in the right order. If the choice rests on a number, like a cost or a finish date, the book's SOLID tool is Guess Alone, Then Talk. Everyone writes a private estimate with a one-line reason before anyone speaks. Then you talk, with the most senior person going last. Then everyone writes a second private estimate. Keep both averages and check which came closer once the real answer arrives. Why the order? Averaging guesses made alone has been shown to work again and again. A 2011 study by Lorenz and colleagues found that seeing other people's answers first can make a group more alike and more confident without making it more accurate. ## Where the book takes your decisions further This is the problem [Mental Models That Actually Work](/books/mental-models-that-actually-work) was written for. Ada Fenwick checked 40 tools against their sources and gave each one a badge for how much evidence stands behind it. **How to Use This Book** explains the badges and sets up the Decision Log, the one notebook that ties every tool together. **Consider the Opposite** has the five-minute card for the "why might you be wrong" question, with the studies behind it and the three-reason limit. **One-Way and Two-Way Doors** gives you the door sort, plus a warning from research on choices you can change: keeping a door open can make you like your pick less. **The Decision Selector and the 30-Day Plan** is where to start if a choice is on your desk today. It points you to the right tools in order, then gives you a month of short drills. ## Where this is in the book - How to Use This Book - Consider the Opposite - One-Way and Two-Way Doors - The Decision Selector and the 30-Day Plan Kindle: https://www.amazon.com/dp/B0HKYJRWMN Paperback: https://www.amazon.com/dp/B0HMNHRGDC Links go to Amazon. ToolGenX publishes this book under a pen name and earns from every sale. ## Is the book for you? - Yes, if You keep making the same kind of bad call and want a way to stop - Yes, if You have read about mental models and want to know which ones hold up - Yes, if You like short, written steps you can do in ten minutes - Skip it if You want someone to tell you what to choose about money, health or law - Skip it if You want a big theory of the mind instead of tools to try this week ## FAQ ### What is the best way to make better decisions? There is no single best way, but two habits cover a lot of ground. Sort the choice by whether you can undo it, so you spend care where it matters. Then list one to three reasons you might be wrong. The second habit has been tested many times and helped in each case the book reports. ### Why do I keep making the same bad decisions? Often because you never see your own pattern. After an outcome, memory quietly rewrites what you expected. A 2004 review of 95 studies found this effect, called hindsight bias, again and again. Without a written note made before the result, you feel you knew it all along and the lesson slips away. ### How long does it take to get better at decisions? The book has a 30-day plan with drills of ten to twenty minutes a day. Every seventh day is a review day where you learn nothing new and only read your notes. If you miss a day, you pick up where you left off. ### Should I think longer about every decision? No. Most choices are cheap to undo and deserve a quick call. Save the slow, careful process for the few you cannot walk back, like a long lease. Using the heavy process on everything just makes you slow. ### Do mental models really work? Some do, and the evidence varies a lot. Of the 40 tools in the book, 6 have strong support, 20 have real but thin support and 14 are documented habits nobody has tested yet. Knowing which is which tells you how much weight to put on each. ### Is a pros and cons list a good way to decide? It is a start, but it tends to leave you too sure. In a 2010 study with 178 students, a pre-mortem, where you imagine the plan already failed and list why, lowered confidence in a plan about twice as much as listing pros and cons. One of its authors invented the pre-mortem, so the book rates the tool PROMISING, not proven.