I was cleaning my bathroom just now with a bottle of spray cleaner. I put the cleaner down for a moment and bent down to scrub a surface. I heard a momentary clatter, looked up again – and the cleaner bottle was nowhere to be seen. At all.

After some searching, and some headscratching, I recovered it from the neighbour's back garden, by knocking on their door and asking nicely if they could check whether it was there.

I had put the bottle down on the bathroom window sill, which is wide enough to use as a shelf for storing all kinds of stuff. The window was open. The bottle was nearly empty, hence light enough that a mild gust of wind could just conceivably have knocked it out of the window. In nearly 14 years of living here, that's never happened before, so it seemed pretty unlikely, especially since no such gust of wind had been perceptible to me; but by the Holmesian principle of elimination (it most certainly was not anywhere in the bathroom any more), I concluded that, no matter how improbable, that surely had to be the truth.

But just below the bathroom window is a sloping conservatory roof. After ruling out it having come to rest on that roof, and also checking if it had slid down the roof slope and fallen just off the edge into an awkward hard-to-reach part of my garden, the Holmes principle again (with an even stronger ‘no matter how improbable’ clause) said that it must have bounced on my conservatory roof, and somehow achieved enough boing to get all the way over the fence into the neighbour's garden.

And it had! Good job too – if I'd gone to the neighbour with that question and it hadn't been there, I'd have sounded even sillier than I did.