If greed or fear has played a role in your investing decisions, (and for most investors the answer is yes, greed and/or fear has definately come into play) then this NY Times article called How Greed and Fear Kills Returns is a must read.

Be a contrarian when managing your investments and take reporter Carl Richards advice, "It makes far more sense to ignore what the crowd is doing and base your investment decisions on what you need to reach your goals, then stick with the plan despite the fear or greed you may feel."

No one said it would be easy.