Stranger to friend

my parents always tell me never ever speaks to a stranger while I were still a little kid. that's why I never to talk to a stranger  when I were a kid. as a grown up person... now I understand, actually this advice is use to scare little children. for me now, if we never talk to a stranger, then we will never be friend. there's goods & bads about this advise. EVERYBODY IS A STRANGER TO EVERYBODY. we never knew each other before. after we talk to 'that stranger', then we know each other. from a stranger to friend. husband & wife also a stranger to each other. from a stranger to friend then, husband & wife. be brave to speak to a stranger. we'll never know what will happen if we speak to 'that stranger'. may be the most interesting part of our life is yet to come...
little children: listen to your parents advise