In reading Julie's comment, I remembered that I forgot to note that we still do look forward to that 18th birthday. Not because it gets easier, but because it is different. We are no longer legally responsible. It is such a freedom to know that there will be no more threats to our financial situation because of the behavior of our children. It's great realizing that the Child Protection System is not going to sweep in and blame us for what they have been doing. We are no longer required by law to feed or clothe them or let them live with us.
And so yes, that makes it a relief... it is different world when you don't have to worry about those things -- a kind of freedom -- but it also makes it morally ambiguous.
So 18 is not a solution, but it is a relief. So keep counting the days Julie. ;-)