You can’t see what is hidden beneath the surface. You cannot see what has been clouded by the passing of time. Everyone you cross paths with has their own struggle. They are combatants in their own private battle, their very own war. But this fact is hidden. You conceal your trouble with a mask of civility, by putting on a brave face and pretending all is well. So do they.
You do not know the demons they strive against. Their family may be imploding. They may have lost their job. Their relationship could be crumbling. They could be trying to figure out how to navigate the minefield of success. Or how to survive failure and humiliation. They could be considering a tough choice, debating, anticipating the difficulties that arise from choosing one path over another.
You know little about them. So do not be too quick to pass judgement or form impressions.