What do you think is the most important philosophical concept for the average person to understand?

What do you think is the most important philosophical concept for the average person to understand?<br><br>This is in the context that there is a concept that can help you navigate life and if you knew that you would be better off. <br><br>For example I think knowing that pleasure is the cause of life and pain is the opposite is super helpful, it's very useful for everyday life to know that and know how to deal with those feelings.<br><br>What is the most important philosophical concept that you think is important for everyday life to know?