A moral being is one who is capable of reflecting on his past actions and their motives - of approving of some and disapproving of others.
'After 17' is a song I wrote when my first daughter went to college, so that's kind of where I'm at in that part of my life. If you listen to that song and knew anything about me, you'd say, 'Oh yeah, he wrote that about his daughter,' but I try not to write them that they are so specific that they