As I was growing up, my family had a couple of sayings I took for granted were universal, at least within my language. As I became an adult I have learned that these are not universal at all:
the ketchup effect. It is an expression meaning that when things arrive, they all arrive at the same time. Think of an old school glass ketchup bottle. When you hit the bottom of it, first there is nothing, then there is nothing and then the entire content is on your food.
faster than Jesus slid down the mount of olives. Basically a saying that implies that the mount of olives is slippery due to olive oil and Jesus slipped.
What you lack in memory, your legs suffer. An expression meaning that when you are forgetful, you usually need to run back and thus your legs suffer.
70's kid my Dad says "wadda want eggs in your milk?" (still to this day)
always said if you "upscale" something.
Me: Dad I need shoes
Dad: ok we will get some.
Me: how about those Adidas like Run DMC
Dad: Wadda want eggs in your milk too
funny thing is as dumb as the saying is. My oldest child used it the other day when a person was trying to merge in front of him