Remember Eeyore from Winnie the Pooh? His most famous line, or certainly one of them, was "Doing nothing together is what friends are for". Have you ever been with someone, and wished nothing more than to simply be with them? Where you didn't want to do anything with them, just be together? Ok, so what's up with that?
Research has shown that in the presence of someone completely trusted, certain changes take place in the body. Respiration and heart-rate dropped dramatically, muscles relaxed, and the senses became dulled. It's almost as if your body shuts down all auxiliary systems, and puts the essentials into a low power state. This state is beneficial to the body both as it promotes repairing, and as it relaxes the mind. If both people were to enter this state simultaneously, the result would of course be highly dangerous. During normal sleep, the human body is still sensitive to the presence of smoke or having a small animal crawl across it. The solution of course is to be able to guarantee a 100% safe environment, or to have one person still fully alert at all times.
How can doing nothing with someone be better than doing something with anyone else? I think we now know.