This accounts for our reaction to seemingly simple innovations like plastic gargabe bags and suitcases on wheels that make life more convenient: "How come nobody thought of that before?"

这就解释了为什么当我们看到像塑料垃圾袋和带轮行李箱这些让生活更方便且看似简单的发明时，我们的反应是：“为什么以前没有人想到这个?”