They get angry, they get quiet and pull back, or they lash out irrationally at you or someone with whom they come into contact. Whatever coping skills life has taught them emerge. When we are faced with someone else's coping skills, we often times react with our own set of learned coping skills, and the cycle continues until someone chooses to put a stop to it.
However, when people are hurting or even less dramatic, when they're not paying attention, opportunities to praise someone go unchosen and unexpressed, opportunities to soothe someone's feelings go unnoticed, and opportunities to spread joy go left undone.
Just as when we're unhappy, being lost in one's own thoughts can also backfire. Then we wonder, what happened here? What's wrong with that person? and the whole cycle begins anew.
One trick I use is to imagine a future experience I want. I go to that future, take a look around, get a feel for the place, and then after I've connected to that energie, I look back at the steps I took to get there - and then I go easy on myself so that I can help pave the way for a softer journey.
I tell my kids to imagine everyone they meet as if they were meeting them in kindergarten. "Remember their face," I tell them. "See them as a little kid. Once you do that, it's easier to see their heart."
In this respect, you never know when you're meeting a survivor. You know who I'm talking about, the main character of a movie we're watching who has unfair battles to fight or little puppy that got lost in the woods because they feel out of the little girl's basket.
These are the one's that we're always rooting for. We want them to get to their happy ever after. Once they're there, the movie ends, the credits roll, and we get up from our seats with some inner knowing that they're going to be just fine.
If your intellect or religious beliefs tell you reincarnation is bunk, then man up, be mature about it, know with conviction that every being on this planet woke up one day and said, "Where am I?"
In this sense, others can help us along the path, encourage us on your daily journey, and potentially play a role in our getting to where we want to be... while we, in return, know that our interactions are simultaneously helping them do the same.