The friend you haven't seen for a year
At the far end of the stretch there's a different kind of open message, which is a friend with no message at all. You haven't spoken in a year, or three. There's no question waiting, no cake, nothing to reply to. There's just a name and a warmth and a growing sense that contact would now need to be a catch-up, a big message or a long call covering everything that's happened, and you haven't got the afternoon for that, so the name stays a name.
This is the surcharge grown up. The catch-up is the proper reply with a year's interest on it, and it's just as fictional. Nicholas Epley and colleagues, reviewing the research on why people connect less than would be good for them, describe a pattern they call undersociality. People expect others to respond less warmly to their approaches than they do, and they name three reasons. The two people construe the approach differently, so the sender is thinking about how it'll look and the receiver about how it feels. The sender can't be sure how the other will respond, and treats the uncertainty as a warning. And the sender rarely finds out how it would have gone, because the approach they don't make gives them no information, so the expectation never gets corrected. Every one of those applies to the friend you haven't seen for a year, and the third is the trap. You never learn that the message would have been welcome, because you never send it, and so next year the stretch is longer and the expectation is the same.
Add chapter 6. Liu and colleagues found the underestimation of appreciation was largest for contact that was surprising and between people who'd grown distant. A friend you haven't spoken to in three years is the most surprised and the most distant person you could write to, and by that finding the person whose gladness you'd most underestimate.
So the pick-up doesn't need the catch-up. It needs a line, and the line can name the stretch or not. "Saw a poster for that band and thought of you. How are things?" Nothing about the year. Nothing to explain. The catch-up, if it happens, happens in the room, at the drink you'll arrange in the third message, where a year of news takes an hour and is a pleasure rather than a task.
And when you meet, it'll go the way it always goes, which is warm and a little effortful for ten minutes and then fine. Chapter 8 said friendship doesn't keep. It also doesn't vanish. It settles, and one afternoon lifts it most of the way back, and the afternoon doesn't need a year's message to book it.