There is a particular constant about moving into a new house.
That is, in the period between meeting the current owner/landlord and saying "yes, what a nice house this is, I think I will definitely buy/rent it" and actually moving in, the vendor in question will zip round making all the rooms smaller, the rooms darker, and the carpets and walls generally nastier than you remember.
In fact my top tip if you are looking around a house with a view to prospective purchase/rent is to make a very secret mark thing somewhere hidden. That way, when you eventually move in you can check that you're actually in the place that you originally saw rather than a cheaper substitute dwelling that you've been tricked into purchasing via a system of mirrors etc (which is quite easy to do).
Fortunately, Narcoleptic Dave's cottage is much as I remember it - in fact he's given it a nice lick of paint. He'd been staying there whilst his own builders finished off, and hadn't really bothered to move much furniture in, with no cooker, and mattresses slung on the floor in lieu of a bed. God knows how he got any sleep.
So thinking about it, there isn't a particular constant at all. It just happens sometimes, depending on circumstances. Like in particle physics (I think, although I am not entirely sure, not being a particle physicist. But I could look the subject up on Google and become an expert, if I had time, which I don't, but I could).
A real particular constant constant, however, is the fact that every single time I move house I say to myself "next time, I will get the professionals to do it." Hence, I have booked the bloke in the next village who owns a van, and asked Short Tony and Big A to give me a hand. There can't be much carrying to do, really.