Carl Jung, the first person to create a personality typology and to popularize(create?) the introvert/extrovert dichotomy, insisted that engaging your "opposite

Carl Jung, the first person to create a personality typology and to popularize(create?) the introvert/extrovert dichotomy, insisted that engaging your "opposite" type is important for personal growth. "Live what you have not yet lived." That said, he also believed that people do have relatively fixed personality types on a fundamental level - you have both traits(introversion and extraversion) but are inclined to express one more than the other. I don't know if he thought it was impossible to drastically change from one end of the spectrum to the other on a fundamental level, but I know he spoke of cases where peoples superior trait was suppressed(e.g an extrovert might suppress their extroversion if they had bad/traumatic experiences interacting with the outer world) - in those case someone can appear to be an introvert and then reclaim their natural extroversion later in life after dealing with the underlying complex related to their suppression. That's just based on his model of the psyche though - maybe he's wrong and there is no real difference fundamentally, and intro/extrovert is simply a matter of what you express throughout your life without some deeper aspect of the personality guiding it, but his explanation makes more sense to me