This is also true of parenting

I like this thought from A.Word.A.Day:

A teacher is one who makes himself progressively unnecessary.
-Thomas Carruthers

One of the big goals we have for our children is that they are functional adults and can stand on their own by their early twenties.  We love them enough that we don't want them living with us for the next thirty years.  It is different if there is some emergency, but for most situations we hope our children will be adults and able to live on their own.