Parents spend way too much time thinking about how to make a dent in the mountain of toys that piles up during the first couple of years of a child's life.
We shuffle awkwardly into charity shops laden down with bags, spend hours composing zingy eBay or Freecycle listings, and as soon as a friend or relative announces their pregnancy, we start mentally compiling a list of exactly what we're going to lump them with.
And if these fail, there's always the garage. Parent Law No. 176 states that the only cars that are kept in garages nowadays are plastic and made by Fisher Price.
So it's easy to end up in a constant cycle of toy replenishment: newborn stuff leads to 6-month-plus toys, then 1+, 2+ and so on. And even if you're parsimonious when it comes to buying them, your family won't be. Hence the theory of getting rid of old toys as soon as your child loses interest.
However, it's a mistake.It's a mistake for a few reasons. First and most obviously, you might have another child - which is where the loft comes in. Second, some of those toys might be worth something. This is a specifically Dad hope to have, usually against all the evidence. It requires faith that in 2045, The Antiques Roadshow will be replete with grubby Iggle Piggles that smell of decades-old saliva.
But the third reason not to get rid of toys too soon is that your child will come back to them. It's something I've discovered recently, after accidentally leaving a basket of charity-shop-bound toys by the front door, which were then discovered by my two-year-old.
It's like they're new toys. Shaky bell things that bored him after a couple of weeks last year are now reborn now he knows they can be thrown across the room at cats. Once-discarded books are being read and re-read several times a day now he can shout out colours and animal names.
And he can finally play that xylophone. Well, I say play...
It's encouraged us to dig other old toys and books out, many of which have been received rapturously as if new. It seems a rotation policy isn't just something that benefits Premiership footballers.
The only trouble, of course, is that this discovery has crippled our plans to reduce the toy mountain to more of a hillock. And while it might mean we don't have to buy any new toys, that's a nigh-impossible policy to enforce on the average doting grandparent.