> I never imagined it lying down nor do I see what that adds to the metaphor. I'd always interpreted it the same was as the author, meant to emphasise a long r

> I never imagined it lying down nor do I see what that adds to the metaphor. I'd always interpreted it the same was as the author, meant to emphasise a long relatively flat period followed by a sudden upwards trend. I think likely because I've mostly heard it used in relation to climate change, rather than economics where it's apparently more often used with your interpretation.