I heard this term on a mothering board I am on. It refers to the last child, but specifically, the last child that comes maybe unexpectedly, maybe not, but certainly a number of years after having a clump of children. I have a caboose (no comments here about my backside necessary!) and I love having her. By the time the caboose comes a long, a mom has learned a thing or two, a mom has calmed down a notch or two.
I remember when the triplets were two I thought to myself, "If I knew they wwere going to actually stick dirt in their mouths when they were two, I wouldn't have spent so much time boiling nipples when they were babies." I know this now. I know that they aren't always going to want to snuggle with me. In fact, there will be a time when they won't even fit in my lap. I know that I can't control every little aspect of their life. Oh, it seems so easy when they are babies. I can control what she eats, when she sleeps, where she sleeps. But, that period of total control is long gone from the lives of my other children now. They will one day sleep through the night, they will one day use the bathroom on their own and get their own food. I will one day be able to go to the store without packing a million and one things in a diaper bag. In fact, I'll be able to go to the store without them at all. And, I know most of all, that when those things are gone, I am going to miss them terribly.
And, so with my caboose, I relax and enjoy. I enjoy every snuggle, I let her sleep in bed with me or worse yet, right in my arms. I let her enjoy lots of foods just for the thrill of seeing her experience them. Because I know that food battles are bound to come and I know that my children have still managed to grow OK. I enjoy temper tantrums because I know that there are many more confusing character qualities yet for her to develop. I even enjoy every bump and bruise she gets, because these physical wounds are so much easier to deal with than the emotional ones that I know are in her future.
I am thankful for my engine kids...the ones who are first in line and keep things moving and pave the way. Together we experience the new challenges and joys of life. I am thankful for the middle car, too. There's always a lot of activity going on in the middle cars...laughter, comraderie, and that drive not to be forgotten or overlooked by the others. (as if we could!). But, that caboose...I think everyone should have one. BTW, mine is 8 months old!!