Introverts are offered keys to private gardens full of riches. To possess sucha key is to tumble like Alice down her rabbit hole. She didn't choose t… - Susan Cain

we can stretch our personalities, but only up to a point. Our inborn temperaments influence us, regardless of the lives we lead. A sizable part of who we are is ordained by our genes, by our brains, by our nervous systems. And yet the elasticity that Schwartz found in some of the high-reactive teens also suggests the converse: we have free will and can use it to shape our personalities.
These seem like contradictory principles, but they are not. Free will can take us far, suggests Dr. Schwartz’s research, but it cannot carry us infinitely beyond our genetic limits. Bill Gates is never going to be Bill Clinton, no matter how he polishes his social skills, and Bill Clinton can never be Bill Gates, no matter how much time he spends alone with a computer.
We might call this the “rubber band theory” of personality. We are like rubber bands at rest. We are elastic and can stretch ourselves, but only so much.

While extroverts tend to attain leadership in public domains, introverts tend to attain leadership in theoretical and aesthetic fields. Outstanding introverted leaders, such as Charles Darwin, Marie Curie, Patrick White and Arthur Boyd, who have created either new fields of thought or rearranged existing knowledge, have spent long periods of their lives in solitude. Hence leadership does not only apply in social situations, but also occurs in more solitary situations such as developing new techniques in the arts, creating new philosophies, writing profound books and making scientific breakthroughs.

Pay attention to what you envy. Jealousy is an ugly emotion, but it tells the truth. You mostly envy those who have what you desire.