Fear is has been the major enemy for thousand of years for the prosperity and a quality life of people. There is no doubt that fear helps to survive, when human beings lived in the jungle-like primitive way. But no higher achievements can be driven by fear. You cannot love from fear, you cannot be happy because of fear, you cannot be inspired to creative discoveries from fear.
Worries too consume valuable energy and time in superior achievements. They do not really help. It is said that worries is like a chair from stone. It makes you twinge and feel uncomfortable, but it leads you nowhere.
