First we state that girls require time and money.

Girls = Time x Money

And as we all know “time is money.”

Time = Money

Therefore:

Girls = Money x Money = (Money)²

And because “money is the root of all evil”;

Money = ?Evil

Therefore:

Girls = (?Evil)²

And we are forced to conclude that:

Girls = Evil

A problem with this “proof” occurred to me immediately: Since evil is
negative, the square root of evil must be imaginary, which would mean
that money is imaginary, and therefore, by definition, so is time.
(Note that this “equation” was written by some guy on the internet, not me.)