"I can't help comparing"

You'd agree with all of this and say it doesn't help. The comparison runs on its own. The song comes on, the sigh arrives, and you didn't decide anything.

It runs on its own the way any habit does, which is on a trigger, and triggers can be seen. Here's a rough list, and yours will differ. A song from the years. A photograph. A smell. A news story about something that's changed. Someone your age saying "do you remember". A young person doing something you find baffling. Being tired. Being alone on a Sunday afternoon. Wildschut's finding in chapter 11 adds two that you might not have listed, which are low mood and loneliness, and they're worth noticing because they mean the comparison arrives most reliably when you're least able to argue with it.

An earlier book in this series is about comparing yourself with other people, and its method is to notice the moment of the comparison and ask a question of it. The same works here, and the question is "what was wrong that year". Not as a way of spoiling the song. As a way of putting the whole record next to the golden version at the moment the golden version is making its case. The song can play. You can enjoy it. And while you're enjoying it you can remember that the year it came out was the year of the bad flat, and the song is still good, and the year is now the whole year.

There's a second move, and it's for the sigh itself. When "it'll never be like that again" arrives, add one word. Yet. Or add a question. Like what, exactly? The sigh is vague on purpose. It's comparing today to a feeling, and a feeling can't be argued with. Ask it for specifics. What was it like, that you're saying it'll never be like again? Warm, with friends, on a beach, with no responsibilities. Two of those are available this summer. One of them isn't and never will be and wasn't as pleasant at the time as it sounds, because no responsibilities meant no money.

You can't stop the comparison arriving. You can stop it finishing. The golden version needs you to accept its account of the year without checking, and the check takes four seconds, and it's the question. That's the whole of chapter 20's method, applied at the moment it's needed, and after a month of it the sigh gets shorter, because it's stopped being allowed the last word.