'Friends' vs documentaries about the Nazis – or how my dad and I watch telly

Just as I battle with my 79-year-old father in his flat in Carlisle, a "Friends Fest" invitation arrives for me to spend time in Monica Geller's apartment and watch her give swing dance lessons – Monica the petite, chopsy, dustpan-wielding, wise-cracking, formerly fat, now bony brunette in the hit TV series. Everyone knows this.

For the 20-to-40 age group, endless reruns of Friends on the Comedy Channel are like national televised diazepam. As soothing as a warm lavender bath after a little cry. So while deadlines, unpaid bills and the thought of phone calls I need to return bear down on me, I can be found on my sofa at 3.15pm observing Chandler and Joey winning Monica's apartment in a quiz about themselves. No, Rachel – Chandler isn't a "transponder". That's not even a word. Or watching the one where Monica becomes the official test chef for Mockolate. Or the one where Ross gets suspended from his museum job after the theft of his Thanksgiving leftovers sandwich, including a layer of gravy-soaked bread. Monica calls the layer "the moist-maker".

I've watched these episodes at least a hundred times since 1995 and still cackle loudly at punchlines I can recite parrot-style. My father, on the other hand, has no feeling for my imaginary Greenwich Village chums. He doesn't quite get the significance of a fancy London invite to a set of Monica's apartment, built for PR purposes to excite media bigwigs and rabid fans. "They're a bunch of American prats," my father mutters, searching for his "buttons" down the side of his chair and then swatting at the screen in search of the History channel. To his relief, Hermann Goering's family cine film is being ghoulishly dissected, starting at 4 o'clock.

Three or four times a week my father watches Hitler sending Nazi agitators into Austria and generally running rings around Chancellor von Schuschnigg. This is his Friends. It's The One Where Everything Gets Incredibly Awful and Almost Everybody Dies. I've begun to wonder if the "incredibly depressing history" obsession stage reaches all of us in old age. I use Friends to turn away from life – from abject reality. My dad prefers to spend his twilight years knee-deep in unpalatable truth.

"Father," I say, in that voice I do almost all the time when visiting nowadays, the one that sounds like a fractious Carry On Matron or a Barlinnie solitary confinement guard. "I'm not entirely sure all this Hitler is good for a person." "Oh leave me alone, I'm happy," he says, eating Lidl mixed-meat paté on thickly buttered toast while watching grainy footage of a Nuremburg rally. Along next, I note, is Hitler's Secrets. I'd hoped we knew the worst about Adolf by now, but no, it seems there are still more surprises in store. I open a window, and Dad closes it. I snap a light on, in protest at the darkness. I make a pot of tea, bring in the Mint Viscounts, and we watch some poor buggers in Dunkirk. "I've seen this one, Dad," I say. "I know how it ends." He laughs at this joke because we always do.

When I was very small – four or five perhaps, and he was a 40-year-old squaddie, I'd watch television each night tucked under his armpit, sitting as still and silent as a statue, because if no one noticed me I could stay up much later. We'd watch Kenny Everett, Columbo, and Cannon and Ball. We'd watch Juliet Bravo, Blankety Blank, and a show about a daft policeman called Rosie. "I know how this one ends," my father would say. "I've seen it before. Rosie falls down a rabbit hole and meets a massive bunny."

Dad's "spoilers" would be complete claptrap, but they livened up an evening when he'd probably rather have been at darts night in the Red Lion. We have spent the greatest part of our relationship watching telly together. But now he finds my tastes infuriating. I find his viewing schedule gives me traumatic stress.

"Why are they always in this bloody flat just twaddling on?" Dad sighs as Ross chivvies Rachel and Phoebe to get ready for a museum function. I've taken possession of the remote control momentarily. It's The One Where No One Is Ready. Possibly the greatest Friends episode ever, if you ask me.

"They live there," I tell my father. "They're flatmates. The boys live in the flat next door. This is a good one." "These bloody Americans," Dad says. "Always so loud. And that false laughing after every-thing they say. Drives me mad." Soon we are back in Hitler's bunker, where the LOLs are, quite frankly, few.

On the Virgin Pendolino back to London I drink a large gin and tonic and ponder family dynamics, ageing, and my own futile quest for immortality. That's the problem with switching off Friends, even momentarily. One has to bother with actual thinking. Thank God for Friends on Comedy Central. Even when it's pouring with rain and the sky starts to fall, they'll be there for you. µ

@gracedent