Sometimes, despite our unhappiness, we are so scared of change that we end up making not only ourselves miserable but those around us as well.
In the words of Deepak Chopra “When the pain of being the same becomes greater than the pain of being different, you change.”
I am not talking about times where you are sad. As Neale Donald Walsch points out, there is a difference between being sad and being unhappy. Life brings us moments in which we choose to be sad, like the death or sickness of a loved one. I agree with Neale that, in these moments, we are happy to be sad because it says something about who we are: we are love. It is not these moments that we are talking about here.
Life is meant to be an adventure. It is supposed to thrill you and bring you joy. Be brave enough and loving enough (to yourself and others) to move on, when necessary.