One of my favorite books is Flow: The Psychology of Optimal Experience by Mihaly Csikszentmihalyi.

I stumbled across this book a few years ago, and when I started reading it I couldn’t put it down. It was like stumbling across the Holy Grail of interaction/UI design. I must have read this book 10 or more times. Even though it is not written as a interaction/UI/UX design book, it has proven to be one of my most valuable resources. Why? Because it is the only book I have found that breaks down the actual psychology behind achieving optimal experience. In the book Csikszentmihalyi explains how we as humans strive to achieve a state of flow in whatever we do, be it working, playing a video game, filling out a form, whatever, and once we do achieve this state of optimal experience, we get this intrinsic feeling of happiness and contentment….pure joy…. The problem with achieving this state of flow is that it doesn’t always happen in every day life, so he breaks down exactly what factors go into achieving this optimal state of flow, in an attempt to teach his readers how to attain it more easily. As a UI designer, being aware of these factors for achieving optimal experience allows me to design my flows and interactions with optimal experience in mind.

If you do not have this book in your design library, you need to go out right now and buy it. The insights you will learn from this book are invaluable.