"Anything can happen day." I guess it was a Micky Mouse Club Show thing. Before my time. "Today is the day that is filled with surprises; nobody knows what's gonna happen."
Of course, you find out that every day is anything can happen day. Every single day. And that means birth & death and everything in between. So in one sense we are all Mickey Mouse Club members, whether we want to be or not. "Nobody knows what's gonna happen" can start to sound pretty damn ominous.
Lots of our days have the "same day" feel, maybe human beings try really hard to make their days the same. We thrive on routine. Society demands routine. If you have a job you lock into a daily grind. We hate it and love it. Gives us something to do, fills our lives with sameness.
And then Anything Can Happen Day comes along and knocks a hole in your reality. And you realize there is no sameness at all. Every day is chock-full of surprises. There's the joy and the horror. The sorrow and the pity. We get ice-cream and cake, and bullets and funerals too.