The strangest thing to say to someone is "no strings attached". Why? Because everything in this world is connected. Everything. We are all connected to each other... one way or the other. These invisible strings that connect us can be stretched, tangled and sometimes snapped. But with every snap comes a new connection.
As humans we are programmed to share our ideas and feel the desire to be heard. That is why we are constantly sending out signals and signs and look for the same from those around us. We are always waiting for messages... messages from near and dear ones. Messages from strangers and even from alien life. Our instincts drive us to establish connections and cherish them. It is why we now rave about Facebook and other social networks that help us connect, send and receive acknowledgments for our every thought.
So, the next time someone says putting out every thought that crosses your mind onto Facebook or any other social network is vain. You just tell them it is a human impulse to share and be heard. There isn't anything vain about it.