Introversion and extraversion are terms first coined by psychiatrist Carl Gustav Jung in Switzerland of the 1920’s. According to Jung, an extravert seeks intensive contact with the outside world. An introvert instead turns the psychic energy inwards. Jung believed that no one is 100% extravert or 100% introvert instead we carry both traits. However most minds tend lean either on one side or the other. If both characteristics are equally present, we can speak of someone who has has an ambivert personality.
Socrates warned against fearing death. He thought it irrational—the fear of death causes you to believe you’re wiser than you actually are. “No body knows death; no body can tell, but it may be the greatest benefit of mankind; and yet men are afraid of it, as if they knew certainly that it were the greatest of evils,” he concluded. His real aim may have been the religious who expressed faith in an afterlife with utmost certainty, a trend still going strong today. 
“Thoroughly unprepared, we take the step into the afternoon of life. Worse still, we take this step with the false presupposition that our truths and our ideals will serve us as hitherto. But we cannot live the afternoon of life according to the program of life’s morning, for what was great in the morning will be little at evening and what in the morning was true, at evening will have become a lie.”
Always Question Authority 