Your computer is running slower than usual? Well, “it’s running like a dog”.
Huh? Have you ever tried to outrun an Alsatian?
Turns out, much like the old phrase “pot calling a kettle black”, there’s a bit that’s been lost at the end along the way… in the case of slow things it’s the words “with three legs” (and in the case of the pots and kettles, “arse”).
So, thanks to the Internet, that one’s cleared up. Although I personally prefer “it’s running like a brick”.