How to be "Strangers"?

Wonder if 10 years back anyone ever thought of the question or ever there was an answer to it which could be so easy and simple. Which could make you strangers in an instant. Which could erase all your memories and wouldn't even let you feel the existence of someone in your life.

All I knew was a book named 'How to make friends and influence people' by Dale Carnegie.

But today its just so simple and easy to achieve all the above that we never thought of few years back.

"Block someone on Facebook or WhatsApp!" :)

Technology rocks and human shocks :D