not be the end of the world
be (not) the end of the world
To be a very big deal or problem. Often used in the negative to describe a situation that one believes is being exaggerated. I know you're upset that you failed a test, but, really, it's not the end of the world! You might think that not getting your driver's license today is the end of the world, but it's not. In five years, you won't even remember this day!