Why do old people stop growing?

I'm reading Teaching to change lives by Howard Hendricks.  In the book, his daughter ask him the question "Why do old people stop growing?" and the question bothered him.  This question has been bothering me as well.  On a personal level have I stopped growing?  Physically?  Spiritually? Emotionally?  Man, I hope not but truthfully I know that I have.  If we stop growing then we start dyeing!  I'm too young to die!  I'm going to have to get intentional about this.  I'm going to have to be open about my growth process and get accountability in these areas.  Tracy always tells me that she loves it when I read.  The reason that she loves it is because when she sees me growing and then she know that I'm going to cause the family to grow as well.  

So I dare you to ask yourself this question as well, "Have you stopped growing in any area of your life and what are you going to do about it?"