Mark enters a relationship with Sophie (Olivia Colman) and finds, quite rapidly, that... he doesn't really like her. This isn't anyone's fault, neither are presented as terrible human beings. They're just fundamentally incompatible and only end up steamrolling into marriage due to crippling mutual loneliness.
Comedy is all about recognition. Michael McIntyre points out one of life's foibles. You recognise said foible, then chuckle lightly and die a little on the inside. But there is a thin, unfunny line between highlighting some hilarious, unearthed observation and lazily trotting out a creaky comedy cliché that was hackneyed when first used on Round the Horne.
"We are unanimous in that," Mrs Slocombe would declare without a doubt in her mind that her team were anything but behind her. What is "Rodney, you plonker" if not the highest term of endearment in Delboy's world? And was clucking Captain Mainwaring not protecting his brood from the Germans when his youngest was urged, "Don't tell him, Pike"?
With the new series of Rab C. Nesbitt about to be unleashed on BBC2 tonight - 25 years after the character first appeared on screen in Naked Video - I thought I would ask the series' writer/creator Ian Pattison some questions. This may prove to have been a mistake. Never mess with a comedy writer...