Joy, sorrow, fear, hate, love, greed and hope are all parts and parcels of emotion. Emotion can make you laugh, cry, perspire, tremble with joy or excitement, or shake with sorrow and even irrationalize your action.
In the stock market and in live, it is important that you control your emotion or else, others will control it. Invest wisely and you will live comfortably by retirement age. Trade unwisely or gamble, and chances are that you will have to work until you can work no more. Choose your own destiny.