A side effect of Motherhood?

Is it possible that a side effect of motherhood is a loss of ambition? I suppose it could be a spurious correlation that has more to do with lack of sleep, but I really am wondering what happened to the vibrant, energetic, ridiculously ambitious woman I used to be? How could it be that I am, for the most part, suddenly content to simply be a mom? I feel like having a baby somehow siphoned off my desire to accomplish something big(ger), like the invisible ambition liquid that used to fuel my engines was washed away with the blood of childbirth.
It certainly is hard to want to pursue wild dreams when I can often scarcely string a decent sentence together, I'm so tired. It certainly isn't helping with any aspirations I have as a writer...and as for on-camera auditioning--forget it, I'm only interested in doing it for money right now, which scares me on many levels. Not to mention the fact that then I'm back on the quest-for-perfection train and I've missed a lot of stops. Now I'm not saying all ambition is completely absent; I've been toying with how I might make and LA pilot season trip viable (and survivable) but at the same time, I wonder if I really want to be away from her as much as I would have to be to be successful in the way that I want. And of course, this brings up a myriad of questions about what to do otherwise, what adventure to embark upon, where to live etc.
I have always clung to the notion of living a life less ordinary like a life raft in a raging sea of potential mediocrity. It seems especially true nowadays that the ultimate sin is to simply live happily and quietly--and I know that it makes it that much harder for me to consider just buying a townhouse (for over half a million dollars, but that's another story) and la-di-da-ing my way through the next twenty years. I want to explore! I want to live! I want to dream big again!
The only question is how? We talk about walking away quite often, and I am the one who is unable to let go and dive into something else. It feels like one of those times in life when you jump off the cliff, flailing against a clear blue sky and hope that the water below doesn't kill you. It feels like the time to embrace something new and exciting (besides having a baby) and yet...I don't really know what it is and I certainly am having trouble discovering it when I barely have the energy to drag my butt to Mother Goose. Ez talks a lot about getting a boat and a bunch of land up North and starting a mothership business and...although it is less ordinary, somehow I can't bring myself to get over excited about living in the middle of nowhere...in Canada. Now if the same scenario were pitched in, say, Costa Rica, I feel like I could jump on board. Why is that? Why, for me, has everything always had to be the most, the furthest, the oddest? Where has it really gotten me? While I suppose it has technically taken me around the world--living in Ireland and Paris, filming in Istanbul, partying in New York, kayaking in the Yukon--hasn't it also broken my heart in so many ways? There is a reason I don't watch scripted television--it reminds me too much of all the 'coulda been a contenda' possibilites, all the ifs and wishes and coulda-shoulda-wouldas. Now it goes without saying that everything I have done has led me to this beautiful and remarkable child, and I know it is my journey, but still...how do you know when to jump once things get more serious? I guess ambition is a double-edged sword...and mine is very sharp on one side and increasingly dull on the other...