But pi is a celebrity numerical phenomena it is simple and basic enough to be a part of the standard sixth-grade math curriculum, and yet so mysteriously complex that all the supercomputers in the world will never find its last digit.

WSJ: We Can All Have a Slice of Pi | Postmodern Times by Eric Felten

Better yet, these products are so complex and involve so many variables--life span, tax rates, market performance, interest rates--that they're almost impossible for clients to evaluate properly.

FORBES: The new giving game

These innovative structures serve as another wake-up call that competition can hit harder and faster in our increasingly complex yet connected world, and so can opportunities.

FORBES: Connect

Yet even he concedes that these carbon nanomaterials are so complex that it is difficult to predict their properties theoretically.

ECONOMIST: Space-age soot

In New Jersey, elected officials can start collecting their lawmakers' pension once they qualify for it (based on a complex system of accumulating so-called retirement credits), yet stay in office and also garner a salary.

WSJ: State Politicians and the Public Pension Cookie Jar