Why spend your life working on defense when no defense can be made truly impenetrable? Take the offensive – learn the vulnerabilities of the world around you and be the change you wish to see rather than living in constant fear of what may happen to you instead.
Joy, like love, is an impenetrable, God-given state of being. The distinctions between joy and happiness and love and affection are important ones under the notion that happiness is an 'iffy' emotion, a highly dependent feeling both aroused and destroyed by external conditions apart from God. And the distinction between love and affection is parallel to such.