There must always be a balance between fear and greed in betting, because those are the major problem in any betting, while greed makes you selfish, so you want to take all the money in the market, fear deprive you of games you would have won.
Fear is also a major part of failure in betting, as some will want to leave the market I.E not betting on sure games they have seen, maybe because they are afraid the market will take the money they have gotten. But, in all know when to bet and when to not bet. Get a strategy for your gambling.
In gambling, the fear of losing too much money is the cause. Most gamblers stop gambling because of the instability and uncertainty and they want to find a guarantee of winning, but gambling is always a jar full of uncertainty where you have a high chance of losing. Fear prevents you from getting too close to winning. This fear is not just about losing money, it is against the self-esteem of a gambler.
Being consistent with being greedy and being afraid can mean how much you can overcome these negative influences and not allow yourself to be greedy to win again after winning. Or you can become greedy and gamble more out of frustration because of losing regularly.