1: First we state that girls require money and time

Girls = Time x Money

2: And we all know: time is money

Girls = Money x Money = Money ^2

3: And because money is the root of all evil

Money = Evil ^ 0.5

Therefore:

Girls = (Evil ^ 0.5) ^ 2

4: And we are forced to conclude that
Girls = Evil
See? I told you. :)
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Whatever life brings you, bring it on!