Early on in Rock & Chips, a 'prequel' to Only Fools and Horses, someone tells the young Del Boy Trotter: "That's your trouble, Derek, you never know when to stop. You just go on and on."
You could say the same about writer John Sullivan. He never knows when to stop; he just goes on and on poking at the corpse long after all signs of life have been extinguished.
Sullivan wrote the most perfect ending in sitcom history in 1996 when, over the course of three superb Christmas episodes, we saw Del and Rodney finally realise their dream of becoming millionaires.
But five years later, he disinterred them for a trio of ill-advised Christmas specials (they'd managed to squander their fortune on unwise investments) that did nothing but stain the memory of the original.
After that there was the dreadful spin-off The Green Green Grass, which relocated one of Only Fools' funniest supporting characters, dodgy car dealer Boycie, to the countryside.
And now comes this feature-length comedy-drama, set in 1960 when Del Boy, played by James Buckley from The Inbetweeners, is just a teenager and Rodney isn't even a twinkle in anyone's eye.
Del Boy is practically incidental here, though; the real focus of Rock & Chips is his mother, Joan (Kellie Bright), who turns heads when she sashays down the street in her high heels and tight skirt on her way to her job as ice-cream lady at the local fleapit.
Like Del, Joan is a bit of a dreamer, but she's trapped in a stifling two-up, two-down house and in an even more stifling marriage to layabout Reg Trotter (Shaun Dingwall).
All that changes, however, with the arrival of Freddie 'The Frog' Robdal, a suave safecracker who sweeps Joan off her feet. Only Fools fans will know that name; Freddie featured, in spirit if not in body, in an episode about the search for buried loot.
They'll also know what happens next: Freddie gets Joan pregnant and the result is Rodney. Not that this takes a lot of figuring out, since a) Rodney's parentage was always in question anyway, and b) Freddie is played by Nicholas Lyndhurst.
This was about the only amusing touch in Rock & Chips, which was a curiously flat and leaden affair. There were nods to the past -- or the future, depending on which end of the telescope you're looking through -- everywhere.
We see Del mucking about with his mates, Trigger, Boycie and Denzil, all moderately well played by young actors doing reasonable impersonations. Grandad was there, too, already settled in front of the TV in his hat and played by Phil Daniels, who didn't bother with an impersonation.
Del was already showing a flair for wheeling and dealing, picking up American pop records down the docks and flogging "100pc nylon" carpet that causes static electrical sparks.
Sadly, these were the only sparks in Rock & Chips. In his eagerness to wallow in the mythology of his own characters, John Sullivan forgot to write any jokes. Unlovely jubbly.
TOMORROW: Pat reviews Charlie Bird's American Year (RTE1) and watches Nelson's Pillar being blown up (again) in Scannal (RTE1)
Rock & Chips *