"No matter how careful you are, the one risk no investor can ever eliminate is the risk of being wrong. Only by insisting on what Graham called the "margin of safety" - never overpaying, no matter how exciting an investment seems to be - can you minimize your odds of error."

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One problem of the String Theory is that it's kind of a theory which can explain what the problems are, but the problems are such that you can't even pin it down and say this is exactly what it predicts, so lets go out and test it. So, it's not even capable of being wrong, or being falsified, or being showed to be wrong.

— Peter Woit