Every human being has to go through pains. They could be physical pains, then the wound will heal leaving only scars. But there are soul pains that the aftermath of them is extremely terrible.
It makes people lose faith. They do not have much confidence in everyone around them because they have been treated badly by those people . They no longer believe in life when life always pushes them into suffering. They also no longer believe in themselves that they will be happy.
It makes them worry and think more. Because trauma makes them scared, they take precautions to never fall into the same situation as in the past. They think about the past, present, and future. They worry about catastrophes that might come and take them down.
They rejected those around them, even their loved ones. Because pain makes them shrink down, they just want to live in their own world, inside the shell that they created. They would rather be alone than interacting with others. Since their hearts are only filled with pain, they have nothing else to share with everyone.