It's polite to say hello to an acquaintance
John is walking his dog and his neighbor passes by.
John wants to eat lunch.
John introduces himself to his neighbor and invites him over for lunch.
John hurriedly rushes past his neighbor and heads back home and makes lunch.
The neighbor thinks John is a cool guy and invites him to his party.
The neighbor thinks John is unfriendly and doesn't invite him to his party.