Something decidedly odd happened at one of last year’s Proms. In a night celebrating the golden age of the MGM musicals, one of the performers was Seth MacFarlane. The average Prommer wouldn’t have known MacFarlane from a poached egg. And even his devotees wouldn’t necessarily be too familiar with the face. But when in the course of the evening he started singing in a voice for which he is better known, the picture became clear. To some of the audience, anyway: MacFarlane is the genius behind Stewie Griffin.

“Marc Wootton is playing characters in real situations with real people” read the message that followed the opening credits of La La Land, as though Wootton were a comedic Archimedes unveiling his Eureka moment, rather than simply the latest “provocative” British wit to go panning for comedy gold in the murky waters of American embarrassment.

Let’s be honest, you never expect much sense from BBC Three. You don’t count on it for, say, depth of perspective. The channel which each week spews fresh torrents of hectic DayGlo entertainment in the specific direction of a desensitised demographic tends to steer clear of the big subjects. War and such. Girls on the Frontline, therefore, did not inspire much hope. That title. On any other BBC channel, it would have been women, not girls. Still, a camera crew was allowed to follow several women on a six-month tour in Helmand province.

Is Eddie Izzard running a lot of marathons really worth three hour-long documentaries? No, but it was worth watching this first one. Having seen close personal friends gearing up to run the London Marathon, a process involving months of training sessions and muscle-group-specific workouts, it was barely believable to see a patently un-honed Izzard strolling into the Olympic Medical Institute in Eddie Izzard: Marathon Man, confessing that “I’ve run before, mainly for buses,” and proposing to run 1,100 miles round the UK in a month’s time.

There were some odd sights in Christmas Day viewing but none more discomfiting, I’d bet, than seeing a ballerina lying on a physio’s couch having a leg dragged quickly up to touch the side of her head while the other leg lay perfectly still pointing downwards. Can the body really do that? Another weird sight - dozens of people in full 18th-century French costume and wigs dancing in 40-degree heat on a Cuban stage. Meanwhile coachloads of dancers were going down with swine flu and a 45-year-old retired dancer was flown in from Germany to take the part of a 20-year-old.

When is enough? The template usually cited as the perfectly proportioned lifetime for sitcom is Fawlty Towers. It ran for two series, 12 episodes - in and out, no mucking about. The Office deliberately kept the same hours, give or take the odd Christmas special and an entire American remake. Disappearing off the other end of the scale was Only Fools and Horses, which adopted the opposite tack of keeping faith with its characters as the contours of their lives changed.