Through all of my research before having Ada, I learned a lot about having a baby and what to expect. Once she was here, I realized there was a lot that people don't tell you about having a baby that I really would have liked to know. Now that we have a second child, I really wish I would have found out a few things beforehand so I could have better prepared myself, at least mentally.
You do hear that labor tends to be faster with the second child. That's at least a nice bonus assuming you aren't the exception to that rule. You don't hear that labor and delivery might be more traumatic this time since the novelty of the first child has worn off and you're more grounded in reality instead of off in la la land.
No one told me I'd have to train my daughter to use her inside voice so as not to constantly wake the baby. We're working on that now.
Even if you think you are settled into a good routine and have a handle on parenthood, having a second child shakes everything up and dumps it upside down. You're sense of control all goes out the window and you have to start over. That cheaper by the dozen theory might be true if you ever make it to a dozen. For just two, the idea that it is more of the same is complete crap.
You'll meet new moms again, but you'll connect best with those who also have a second child since the first-time moms still have that deer-in-the-headlights look about them.
If you nursed your first child, depending on how long it's been since you last nursed (in my case, a year and a half), you'll likely have forgotten the proper techniques and should refresh your memory or ask the nurses for pointers before assuming it's like riding a bike and having your newborn damage your nipples. This tip could have saved me two weeks of toe-curling pain.
I didn't know that, if you nurse again, you're chest is likely to get even bigger than before and your original nursing bras won't fit. And if they do, they'll be so stretched out from the first time that they don't offer all that much support. Be forewarned that if you share this knowledge with your husband, he may keep knocking you up solely to see just how big they can get.
If you are nursing, you'll likely produce more milk and leak way more than you ever did the first time. Your milk might also let down as soon as your older child cries since your nursing instincts can't always tell which child is crying, they just respond.
You make a lot of mom friends with the first child so that they will all cook you dinner when the second child arrives since you won't have time to cook, or do much of anything for that matter.
If someone is kind enough to send you flowers with their congratulations and well wishes, the flowers won't last as long as they did with your first child since you'll likely neglect to devote the proper time to care for them as you are sure to be more distracted.
With the first child, you are clueless and want your relatives to stay to help as long as they can--for the most part anyway. With the second, they assume you know what you are doing and don't need them as much when in reality, you probably need them even more. You just don't know it yet.
And the real reasons you take less photos of subsequent children isn't that you love them less or that the novelty of a new baby has worn off. It's likely because you don't have time to pick up the camera, you don't have a third hand to hold it with, mommy brain makes you forget it, or you don't have any more room in the diaper bag to take it with you when you go out. Not to mention the fact that, in order to take a picture, you have to get both kids to sit still long enough to focus the shot and snap the shutter or hope that your older child doesn't run away while you pose the baby on a blanket in the shade for his photo shoot.
Moral of the story: You can't prepare for everything so try to stay calm and do your best.