The idiom "The grass is always greener on the other side of the fence" is a common phrase that describes how we often think that other people's lives are better than our own. When we focus on what we don't have, it can make it hard to appreciate what we do have. This mindset can lead us to make choices that aren't in our best interest and make us feel inferior. It's important to remember to appreciate the good things in our own lives and not compare ourselves too much to others.