Wanting to believe in people, then seeing them fail in life.
You want to see the good in them, you really do. But something in them changes. They no longer act the same. Perhaps they start doing drugs or some other bad habit? Whatever is the cause, they start going downhill. Fast. They aren't the person you once knew anymore, or maybe you had them wrong from the beginning and they finally decided to show their true colors? You might never know the true answer to that question. Maybe you'll always wonder.
Eventually, you aren't friends with them anymore. How could you be? Now all you have is a distant memory of what they used to be and the relationship you used to have with them. They had such potential. They were someone you could believe in. Someone who inspires others. A beautiful human being. Someone who makes you see the good in life. No more...
Have you believed in someone and been let down before? Who was it, and how is it that they changed?