I've learned that everyone has a story. Depending on how much they trust you they might tell you their story. It might be someone you've only just met who decides to tell you their story. It may be that you have to slowly gain their trust before they tell you.
You may sit for long hours whilst they tell you all at once. You'll hold their eye contact and see the sorrow in their eyes. You'll need to hug them tight so they know someone cares. You'll hope that they never hurt as much ever again, but ultimately how much they hurt right now is out of your control. The want and need to help will keep you awake at night, but the only thing to do is be there. There are problems in the world that you cannot fix, but can make better.
There will be other people who will drip feed their story. A reference there, a clue here so you'll have to piece it together yourself. A jigsaw of memories that build up a bigger picture. Still one to keep you awake and working out the best version of the future.
However some people will never tell you their story. It's theirs to choose who to tell. Don't assume it means that person has nothing to tell. Every human has a fragility. The most outgoing of people may be hiding the biggest sorrow. Secrets are kept by everyone. We must be mindful of this in our relations with others. You don't know how others will react on the inside. People bottle stories and send them out into the sea of the mind, but some day the waves will wash back and you have to deal with them.
If they trust you with that story hold it close to you. It's a precious sign of confidence in your relationship. It will bring you closer, but value it wisely.
Everyone has a story you just may not know it yet.