Anyone can see a pretty girl. An artist can look at a pretty girl and see the old woman she will become. A better artist can look at an old woman and see the pretty girl she used to be. A great artist can look at an old woman, portray her exactly as she is…and force the viewer to see the pretty girl she used to be…more than that, he can make anyone see that this lovely young girl is still alive, prisoned inside her ruined body. He can make you feel the quiet, endless tragedy that there was never a girl born who ever grew older than eighteen in her heart…no matter what the merciless hours have done.
–Robert Heinlein in Stranger in a Strange Land