Introverts, how do you keep in touch with people who never reach out?

Introvert does not mean socially reclusive hermit who panics at having to talk to anybody.

Introvert means that you recharge and relax in private.

Introvert does not mean being completely socially incapable.

Introvert means that after spending time in groups you need time alone.

We reach out to them. Just like anybody else.