The good old days had problems too
"I was happier then"
Leave the world alone and come back to you. Whatever the surveys say about strangers, you know your own life, and you were happier then. You can feel that you were.
Two things about that feeling. The first is that it's a present feeling about the past, made now, by the fade and the reconstruction from chapters 3 and 4, and that what it reports is how nineteen ninety-six feels to visit, not how it felt to live in. Those are different, and the difference is the whole book.
The second is what the person living in nineteen ninety-six was actually doing. They were worrying. About the rent, the job, the relationship, the thing with their mother, whether they'd ever amount to anything, whether the friend who'd gone quiet was cross with them. They were tired a lot. They had a bad back that year, or a bad flat, or a bad boss. They spent whole evenings on the sofa feeling that life was passing them by. You know this, because you've done the chapter 1 exercise, and the problems came back when you went looking. The person in the photograph was, on the day the photograph was taken, quite likely thinking about something that had nothing to do with the beach.
Here's a test. Imagine writing a letter to yourself in nineteen ninety-six, telling them they're living in the good old days. What would they say? In my experience of asking people this, the answer is some version of "you must be joking". They'd list their problems. They'd say that if these are the good old days then the future must be dreadful, and they'd be wrong about that too, in the same direction, because in twenty years the future will have faded into its own golden version.
I'm not saying you weren't happy then. Some years are better than others and it's quite possible that one was better than this one. What I'm saying is that "I was happier then" is a comparison between a remembered happiness with the problems removed and a current happiness with the problems left in, and that isn't a comparison the present can win, and its losing tells you nothing about either year.
The person you were then wasn't living in the golden version. They were living in the whole record, the same as you are now, and they'd have been astonished to hear it called the good old days. Chapter 22 is about what that means for today.