If x happens (or doesn’t happen), the “sky won’t fall down.”
I’ve always thought that such expressions are useless. If the degree of the calamity that has befallen me is insignificant compared to the sky falling down, how am I to know, to what extent?
It’s an invalid reference because no one has seen the sky falling down. It is, after all, relative to the power of my imagination – which is also not a standard in any case. To make sense of this comparison, I have to imagine an impossible cataclysmic phenomenon to a significant magnitude and then allow my real calamity seem inconsequential – so that I feel better.
Not too helpful for people with shallow imagination skills.
And, too much work, if you ask me.