Fast Minds, Fuzzy Memories: How People Really Think and Why It Matters for Design

Think you’re in control of your decisions? Think again. The science of cognition reveals that most of our choices are made by System 1—fast, intuitive, and emotional. System 2, the slow, rational thinker, only steps in when things get tough. This means that most user decisions happen before they’re even aware of them.

Consider how you remember things. Each time you recall a memory, you change it, adding new details or emotions. This is why eyewitness accounts are so unreliable and why designers must make it easy to recover from mistakes.



Emotions glue our memories together. A website that sparks joy or surprise will be remembered long after a bland, functional one is forgotten. That’s why the best apps build in emotional moments—celebratory animations, encouraging messages, or even gentle humor.

Smart designers assume users will forget, make mistakes, and act on impulse. They build in feedback loops, undo options, and emotional cues that support users at every step. Want to design for real people? Start by embracing the messiness of the human mind.