Okay, so I think you are asking <em>What is the possessive form of the word brushes.</em>
<em>Brushes' </em>
<em>Singular form (brush) = brush's</em>
<em></em>
<em></em>
<em>~theLocoCoco</em>
I believe they are common because people believe that is where we could be headed. Will we run society into the ground, or will we prosper? Will the society be a "Divergent" or "Giver" society or will it exist as it does today? Since we have no way of knowing, we pretend we do.