Real life Twilight Zone
Several Twilight Zone episodes1 are built around one character remembering a reality the rest of the world doesn't. The second half of It's a Wonderful Life has the same basic horror: losing your identity, relationships, memory. Your place in the flow of time.
Some of my core memories, lighthouses of my entire life, aren't remembered the same--or at all--by the people who experienced them with me. I'm not talking about moments of natural asymmetry, like a passing smile from a stranger that you might remember for decades, but they might forget five minutes later. I'm talking about moments that you know mattered at the time to everyone involved. The times that make you believe all the struggle and stress are worth it, and humanity might not entirely suck. The ones you hold on to.
Then imagine being told by the only person who shared the experience that they don't remember. Or that they have memories of times with you that they cherish, that you genuinely can't remember.
I get it, time passes, people remember differently, or overwrite good memories with subsequent better ones2. Some people conflate happiness and mental health as living and experiencing the now, and for them, any kind of backwards-looking happiness trades against that.
It might not be happening with the totality inflicted on Twilight Zone characters or George Bailey, but the everyday erosion and fragmenting of shared memories feels even more insidious. Maybe it's horror, maybe it's life.
Okay, more than several: And When the Sky Was Opened, The Last Flight, A World of Difference, Shadow Play, A Quality of Mercy, Person or Persons Unknown, The Parallel.↩
https://www.npr.org/sections/health-shots/2014/02/04/271527934/our-brains-rewrite-our-memories-putting-present-in-the-past↩