Advice for the kids:

Always talk to strangers.

Strangers are often very nice people, with good intentions, who might have interesting stories.

Why are we so afraid of talking to strangers?

Ah, but it is the stranger who tries to talk to you that we fear. It is not the interesting person in the bowler hat with the monocle, perusing apples, not expecting a conversation with a child, today, that we should fear.

Talking to strangers is fun. It's when strangers talk to you: that's when it's not fun.