soft question - Colloquial catchy statements encoding serious mathematics

"If you are walking between two policemen going to the same station, you will end up there, too."

This encodes the familiar Squeeze Theorem: If $a_n,b_n, c_n$ are sequences of real numbers such that $a_n leq b_n leq c_n$ and $lim_{n to infty}a_n =lim_{n to infty} c_n$, then $lim_{n to infty}a_n =lim_{n to infty} c_n= lim_{n to infty}b_n$.

I am not sure whether it counts as "serious mathematics", but this is how I learned it as a high school student in Communist-ruled Poland.