the Wikipedia page on the subject.)
When I was little, I did, genuinely, watch Dr Who from behind the couch (we weren't posh enough to call it a sofa), so that it was possible to hide when it got really scary. And I was not alone. Most of the young nation used to do this. Yet it is a practice that has pretty much entirely died out. Why?
I had assumed it was because the yoof of today is far more cynical and exposed to horrors that make Dr Who look wimpish in the extreme. But there was no doubt that this Saturday's episode, Listen, was suitable behind-the-sofa material, especially the bit with the bedspread right behind them (you have to have been there). If you haven't seen the episode and have access to BBC iPlayer, I recommend it. And then Mr Brown made that simple remark.
Because the fact is, these days, many people do push their sofas against the walls, while back then they tended not to. There could be various reasons for this - fewer squarish living rooms now, and we have much bigger TVs, for instance. But my suspicion is that it could be central heating related. Like much of the UK, we didn't have central heating when Dr Who first aired. In our case not until 1966. Before then, on a winter evening, you didn't want your sofa miles away from the fire. So the seats tended to be more advanced into the room than they now would be.
Of course, this could be rubbish. But it's a theory. And even better, it's a Dr Who related nostalgic theory. What more could you ask?