Another big factor, if not the biggest, in the movie is regrets. It's apparent that the majority of people here on BM (and I think also on DC) are not teenagers or in their twenties anymore. I'd say most of us are not too far from 40 or older than 40.
It's logical: when you're 40, you already have half of your life behind you. You are old enough to have some life experiences. We all make mistakes in our lives, turn the wrong way, make wrong decisions. The longer you live, the more chances to make wrong decisions. Only few people manage to reach 40 without having some things in their life they truly regret.
So regret is another common factor
In a nutshell,,regret,turning right instead of left,realising too late and then having to live with the consquences.The grief and sheer desolation of knowing the clock cannot be turned back.
Coupled with I would guess in several cases a love lost,given up on or just plain impossible.Nothing turning out the way we maybe planned or envisaged it in youth.
In my case coupled with watching my kids and hoping they get it 'RIGHT'.the jealousy of youth and all that promise waiting to reach its potential,in direct contradiction with,in my case the fact that I did not get it right.
Finally the vain hope that just maybe its not too late.At least to make some changes.
For those who view beyond the movie,it can literally be life changing,and in some cases reaffirming.
Very astute writer and observer of the human condition as a whole,depicted by amazing actors and handled with extraordinary sensitivity by the director.
It IS the human condition.To want to love and be loved,and for most of us,to err from the moral highway(unless you are perfect,not me) to experience the guilt associated with that.Then as the years pass to reflect on what has transpired and attempt to put it in some perspective.
The film almost invites/gives permission for us to allow those feelings.Indeed to wallow in them and give full vent.And why not,for many of us they were very painful and hidden for too long.
For those not affected I suspect they are too busy feeling smug about their perfect lives,or portraying that facade.
Sorry if that sounds condescending.I just think some people really feel and others put on very good show of feeling.