To my children, there are no strangers.
We have visited dozens of homes and churches and people in the last 4 months. And of course, everyone already knows who they are. Everyone is a friend. Both Grace and Josiah will now hug and kiss anyone on command. In fact, they will do so even not on command. When they are leaving a home, they automatically hug and kiss everyone in the room. They've figured out that's just what you do.
This does have some ill effects. At the park one day, Grace asked a total stranger to push her on the swings. At Disneyland last week, my kids socialized with everyone around them. ("My name is Grace; What's your name?") I'm kind of surprised they didn't start hugging and kissing them as well.
They've loved it. Quite often when they pray, they thank God for their new friends.