Impossible Expectations & the Planning Fallacy: How to Get Real

This article is an excerpt from the Shortform book guide to "The Power of Discipline" by Daniel Walter. Shortform has the world's best summaries and analyses of books you should be reading.

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How well do you predict what it will take to reach your goals? Do you give up when you fail to make the progress you expect to make?

When we set goals, we also tend to set impossible expectations about reaching them. Then we get discouraged when we don’t hit certain benchmarks along the way. The tendency toward unrealistic expectations connects to a cognitive bias called the planning fallacy.

Read more to learn about setting impossible expectations and the planning fallacy.

Impossible Expectations

Daniel Walter explains that we set impossible expectations by underestimating the amount of time and effort it takes to reach our goals. When we neglect to put the necessary time and effort into our endeavors, we’ll likely fail to reach our goals. This failure discourages us from continuing to work toward our goals in the future, crippling our ability to self-discipline.

When you make the easy decision to give up rather than putting in the time and effort necessary to achieve your goal, you weaken your ability to self-discipline. This is because giving up is another form of temptation and instant gratification. When you practice these habits that are the opposite of self-discipline, they grow stronger while your ability to self-discipline grows weaker.


Your goal might be to learn how to knit. To do so, you need to practice one hour per day for one month. Someone who sets unrealistic expectations might think that spending one hour a day practicing for a week is enough to master the skill. Another person with unrealistic expectations might practice for a month but spend only two hours a week practicing. Both people give up at the end of their allotted time frame because they didn’t put in the necessary time or effort to complete their goal. When they give up and stop trying to knit, they’re giving into temptation rather than practicing their ability to self-discipline, consequently weakening their ability to self-discipline in the future.

How to Overcome This Tendency

Walter recommends taking the time to analyze your goals and the actions you’re taking to reach them. Ensure that you’re not engaging in self-sabotaging behaviors that set you up for failure, like setting unrealistic expectations. Ask yourself what a rational time frame to complete your goal is, what work you must do to achieve it, and how often or when you need to do that work to reach your goal within the given time frame. This realistic analysis will reduce your chance of failing and giving up, thus preserving your self-discipline.

The Planning Fallacy

Experts explain that the tendency to set unrealistic expectations can be linked to an underlying cognitive bias called the planning fallacy. This theory states that people tend to underestimate how much time it’ll take to complete tasks (or reach goals) due to poor planning and overly optimistic performance expectations. They elaborate that this tendency is the result of three main biases:

  • Optimism bias convinces us that we’re less likely to experience misfortunes that might disrupt our plans. For example, we might expect to get to work in 10 minutes because we don’t anticipate rush-hour traffic slowing us down.
  • Motivated reasoning makes us set unrealistic expectations because those are the results we want rather than what’s realistic.
  • Taking the inside view makes us focus on the small details of something rather than the big picture, which can lead to avoidable mistakes.

Further, experts reiterate Walter’s claim that setting unrealistic expectations can lead to a lack of self-discipline. They also provide more detail on why this might occur, explaining that the repeated disappointment of failure due to unrealistic expectations can trigger self-judgment, depression, and burnout. These factors likely prompt the negative thoughts that convince us to give up on our goals—in other words, to give up on self-discipline.

Walter recommends avoiding unrealistic expectations by analyzing your behaviors to ensure you’re being productive and realistic. But, what types of analysis should you perform? Experts make a few suggestions:

  • Take the outside view. To gain a more realistic perspective on your goals, the time and effort required to complete them, and the obstacles you might encounter, seek advice from experts or people who’ve attempted similar goals in the past.
  • Define your priorities. When you plan what tasks to complete and when as Walter recommends, prioritize your tasks and avoid unnecessary work. This will ensure that you’re getting everything done in an orderly and timely manner.
  • Manage your time and resources. Block time off in your calendar to complete tasks and list all the resources that you’ll need to complete them to ensure you’re maximizing your productivity.
  • Consider obstacles. Brainstorm a scenario in which you failed to meet your deadline and determine the obstacles that could have gotten in your way. This will help you take action to avoid this scenario.
Impossible Expectations & the Planning Fallacy: How to Get Real

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  • What self-discipline is and why we struggle with it
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Elizabeth Whitworth

Elizabeth has a lifelong love of books. She devours nonfiction, especially in the areas of history, theology, and philosophy. A switch to audiobooks has kindled her enjoyment of well-narrated fiction, particularly Victorian and early 20th-century works. She appreciates idea-driven books—and a classic murder mystery now and then. Elizabeth has a blog and is writing a book about the beginning and the end of suffering.

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