I'm not sure how helpful it would have been to know this beforehand, but one of the things that surprised me is how much decision making I'd need to do. You're CONSTANTLY deciding things. Is she ok? should we go to the doctor? is she too hot? what clothes should she be wearing in this temperature, should we give her paracetamol just in case it's fever? how much food should we feed her? what food should we feed her? is she old enough to have x? oh x is bad for baby's and gives them gas, wish we knew that yesterday? how do you deal with gas in babies?
The most stressful times are when you need to make decisions but you can't find information, or probably more to the point, you can find heaps of information, but none of it makes it easier to make make the decision. You just have to make one.