They sat in the same room, but not in the same universe. ---Aldous Huxley, The Devil of Loudon
In the moments we come together, we come from backgrounds that contain millions and millions of different experiences and personal interpretations of those experiences. No one can truly know what it has been like to be the person before us. We traveled circuitous routes to this moment in time, to this place, to this person/s. So much has happened that is unspeakable in words. Some can be deciphered by observing and intuiting, but that is not the full picture of a life. I can surmise we share some of life's common themes - love, loss, hope, fear, success, failure, etc., but I cannot fully know the impact or the details. I scarcely can understand my own.
All this to say, we would do well to practice kindness and compassion for all who come into our lives for quick moments or long times, and of course towards ourselves too. There is no way we can fully walk in one another's shoes and comprehend fully the whys and wherefores of those who stand before us. Let kindness and compassion be our guides.