That’s fair. I liked the book, didn’t love it, and that’s probably because while I admired the inventiveness of their communications there wasn’t really much of a story, and I do, as a rule, like books to have a plot.

Man in the Empty Suit by Sean Ferrell.

A time traveller goes to his own birthday party - every year. So the book is, mostly, the same party, over and over again, with him there at successive ages. And there is, of course, a crisis point which happens at a particular age, and so all of his younger selves don’t know the details, but the older ones do.