The good old days had problems too
What the golden version costs you
I've argued the mechanism. This chapter is the bill, and it arrives quietly, which is why it's been allowed to run.
The present, unlived. Every hour in nineteen ninety-six is an hour not spent in the only year you can actually do anything in. The golden version doesn't just dim the present by comparison. It takes time from it, and the time is the thing that in twenty years you'll wish you'd had more of.
The people beside you. The friend on the beach has been compared, silently, with everyone you've met since, and everyone since has lost, because the friend on the beach has no problems and the people since have them. Your partner has been compared with the person you loved at twenty-three, who never left the toothpaste lid off because you never lived with them. Your friends now have been compared with your friends then, who've been edited into the most fun people who ever lived. Nobody can compete with a photograph, and the people who are actually here have been quietly losing to one for years.
Your children, if you have them, hearing the decline story. A child who grows up being told the world has got worse learns that the world they've been given is a poorer one, and that the good time was before they arrived. That's a heavy thing to hand a child, and Mastroianni and Gilbert's seventy years suggest it was handed to you, and it wasn't true then either.
The mood. The sigh isn't neutral. It's a small drop, and it comes several times a day, and several small drops a day is a mood, and Wildschut's finding that low mood triggers the going-back means the mood sends you back for more. That's a loop, and it runs downward.
The decisions. A person who believes the best is behind them makes different choices from a person who doesn't. They don't start things. They don't move, or change jobs, or make new friends, or learn the instrument, because what would be the point when the point has passed. Chapter 16 is about how wrong the forecast tends to be, and this is what acting on it costs.
And the past itself, which is chapter 19.