Ha! Good one!
With the first one, the sleeping thing really is that terrible, especially for ge first three months, maybe even six months. Your significant other is going to be exhausted and may even end up a bit of an emotional wreck from the lack of sleep. You may not have breasts, and it may not make sense, but you'll end up having a role in the process. At a minimum, you'll wake up every time she does. Plus, I suspect that most first time parents are like me in that they will have constant fear that something is wrong with the baby if they don't hear the baby making noise regularly.
It isn't forever, but it will impact you. Don't even fight this fight. It may seem irrational to you, but when fatigue sets in the way it's going to set in with her, rational thinking goes out the window. And that's even assuming no wild hormonal issues or post-petunia depression. It also assumes a smooth breast feeding process, which is no guaranty. My first was born at 34.5 weeks, 4 pounds, 10 ounces. Breast feeding was a challenge. So she was breast fed, then my wife pumped milk. While my wife pumped, I fed the baby the milk pumped front the last round, then supplemented with formula and burped her. That meant 20 minute interruptions to my milkless ass every feeding.