It probably sounds strange, but there’s no better way to put the brakes on your own racing thoughts than to listen to two grown men lying in a bunk bed, rambling on about life and death and everything in between.

That’s the basis of their podcast, Bunk Bed, which first aired on BBC Radio 4 in 2014 and has just finished its ninth series. There’s no structure, only what they describe as a “stream of semi-consciousness,” which gives rise to any number of random thoughts, often silly but sometimes quite profound.

Occasionally a celebrity joins them (series nine has Simpsons voice actor Harry Shearer, comedic actor Jane Horrocks and TV chef Andi Oliver), often revealing more in those 14 minutes than they do in the standard hour-long podcast interviews we’ve been inundated with. And who can blame them for dropping their guard? Splayed out as they are in the dark on a pull-out mattress.

To give you an idea of how the conversation pans out, at the start of episode five of series nine, Curran complains about his sore back, specifically his coccyx. He recalls a time when people referred to it as a “vestigial tail”, which sparks long speculation on life with tails.

What shapes would theirs take? “I like to believe I’d have had a long, slinky, ironic tail, but I suspect I’d have a little stumpy sort of tail that could barely wag,” says Marber. “Yours would look like a platypus.”

Would they be used as a portable tripod to rest your legs? Or kept in zip-up pockets to protect them from the elements?

Just when you think they’ve exhausted that train of thought, after a long pause and a rustle of the covers, “I think the male nipple is the next to go of useless things,” Marber ruminates ruefully. And on we go.