An old but true saying that people come into your life for a reason, a season, a lifetime.
It's helped me have a perspective about life's realities. Cherished friends and family are gone, so it seems, forever. Yet, new friends and "family" have entered my life and I feel good, despite loss. With age comes a sense of contentment. It is what it is.
Regarding an introverted nature and the polar opposite, Mom was outgoing and chatty and Dad much quieter but very passionate about helping people. I feel that mix in me.
Best Wishes.