"Philip met her eyes, and smiled quickly. After which he looked away, and said something she could not possibly have been anticipating. '"What is the name of your goldfish?"'
"Lois frowned. 'I beg your pardon?'
"'"What is the name of your goldfish?" That was the first thing I ever said to you. Do you remember?'
"'No -- when was this?'
"'Twenty-nine years ago. I was round at your parents' house. They threw a dinner party, for my Mum and Dad. You were wearing an incredibly low-cut dress. I couldn't take my eyes off your cleavage.'
"'I don't remember that at all,' Lois said. 'Anyway, I never even had a goldfish.'
"'I know. You were talking to my dad about Colditz, the television programme...'" -- Jonathan Coe, The Closed Circle.
The problem with linking two novels -- this one and The Rotters' Club, in which you can read 'live' the conversation discussed above -- over a gap of 30-something years is that your characters have to keep telling one another their back stories. The advantage is that 'Do you remember?' conversations really happen, and feel less awkward when represented in a double-book.
[The Closed Circle, by Jonathan Coe (Viking, 2004). Second part of The Rotters' Club -- preplanned, so it's unfair to call it a sequel -- set 1999-2003. The less attractive end of the pantomime horse; strong on middle-aged defeat, but weak on Blairism, of which it's in part a satire. The first book's little Thatcherite is now a new Labour MP. Thing is, when he's meant to have been reading Milton Friedman in bed, most future newLabourites were far-left chisellers at the NUS.]