I have a sister who is ten years younger than me. We grew up in the same house - a millstone grit terrace which, thanks to pollution in the city where we were born, looked as if it was made from burnt toast - with the same people around us, and many of the same things. But there was a period when I lived there without her, and another period, later, when she lived there without me. On the surface of it, we should have mostly shared memories and yet, sometimes, when we talk, she shrieks at me in amazement. How fast things change; how quickly the times separate us from one another. She doesn't believe me when I tell her that a rag-and-bone man used to patrol our streets in a horse-drawn cart (it sounds unlikely even to me; I'm only 40, for God's sake), and she hoots with laughter when I describe the hardship that preceded her arrival: whorls of ice on the inside of pre-central-heating windows; the black-and-white telly with programming that began at teatime and ended at bedtime; the joyous arrival of such novelties as Findus Crispy Pancakes.
I thought about all this as I watched Electric Dreams (29 September, 9pm), which is part of BBC4's excellent technology season (words I never thought I'd write; I'm a technophobe, though I do own a Lakeland de-bobbler, with which I keep all my woollens in tip-top condition). Oh, I loved Electric Dreams. It could have been so cheesy, and yet it was so poignant.
Here's the premise. The production team has transported a family from Reading - he is an accountant, she's an NHS executive, they have four children - back to 1970. Their house has been stripped of all its 21st-century mod cons and equipped instead with 1970s consumer durables: a twin-tub washing machine, a rented telly the size of a small cupboard. But there's a twist. Each day represents a year in this experiment, a conceit that allows the Sullivan-Barnes family to take delivery of new bits of technology as they would have arrived on the market. Thus they will move through three decades of innovation over the period of a single month: in the second episode, we will watch them encounter the 1980s; the week after, the 1990s.
The detail was brilliant. The family was, for instance, given a Goblin Teasmade early on, even though in 1971 such an item cost a week's salary. Why? I'd never really thought about why, precisely, Teasmades were once so popular, but Electric Dreams explained the mystery. A Teasmade, it turns out, was a lot less expensive than central heating, a luxury then confined to just 25 per cent of homes. Their owners were merely desperate to avoid the shock of the cold kitchen floor. In 21st-century Reading, in the misery-inducing gloom of an early winter morning, the Sullivan-Barneses' Teasmade roared hilariously to life - and so, I'm afraid, did my sensory memory. As husband and wife lay there, blinking at its cranky plastic bulk while they shivered half to death beneath their blankets, I thought of chilblains. Did my sister ever get chilblains? I bet she didn't.
Later, the family made mixtapes - a stereo music centre having finally replaced their hissing mono radiogram - and took slides rather than photographs, the better to bore their friends with. They ate puddings steamed to death in a pressure cooker and played Pong, a "computer" game by Atari. This was all total bliss for me: I was like Proust on speed (or, perhaps, a Sherbet Fountain). But it was also, to be preachy about it, a reminder of how much we once did without, and still could, if only we used a little imagination. In another programme in the season, Upgrade Me (28 September, 9pm), the poet Simon Armitage tried to find out why people change their computers and phones every five minutes. I liked the way he compared his ancient iPod to a lump of Kendal mint cake in his pocket, but was his question really so hard to answer? We buy stuff because we're greedy and stupid, and because our collective memory is far too short.