Since it is demonstrably true that it is the degree to which events affect your thoughts or move your feelings that they have power over you, it must also be true that to gain control over thought and feeling is to become pleasurably independent of fortune. If you let your life be managed entirely by the hazards and chances of outside happenings instead of by your own intelligence, you imperil it.
Our outward miseries are symbols and symptoms of our inner failures. For every self-created suffering and every self-accepted evil is an avoidable one. It may not depend entirely upon yourself how far events can hurt you but it does depend largely upon yourself. If you had the strength to crush your egoism by a single blow, and the insight to penetrate the screen of a long series of causes and effects, you would discover that half your external troubles derive from faults and weaknesses of internal character. Every time you manifest the lower attributes of your internal character you invite their reflection in external events. Your anger, envy, and resentment will, if strong enough and sustained enough, be followed eventually by troubles, enmities, frictions, losses, and disappointments.
Yes, if you wish to understand the first secret of fate, you should understand that its decrees are not issued by a power outside you, but by your own deepest self.
-- Notebooks Category 9: From Birth to Rebirth > Chapter 3 : Laws and Patterns of Experience > # 101