Its a well known thing that as far as I can tell everyone goes through if they have multiple kids even though they are aware of it. At least I have never encountered anyone who has mentioned it not being the case who has had kids. I guess its that way with sorta everything though. I mean seems like most professionals are more comfortable and easy going with their profession down the line compared to first year at first job.
There's no way to describe the feeling of being told you can leave the hospital with your first kid. My 25 yo SO and I looked at each other like, oh shit. We're responsible for this life and they are totally helpless. There's knowing something, and then there's really knowing.
But yeah, kid #2 was the same but more like, we got this.