Monicad, the God who created us and sanctified the family as an institution also knows the importance of birth order and how that subtly shapes us our whole lives. Where we fit in a family and how we do that has a lot to do with how we fit into the world and how we relate to others. Reading a book like that is not like astrology. It’s an attempt to understand the things that affect us as we grow up.
Look to your bible and see the stories of people who were profoundly affected by their birth order… Jacob and Esau, Joseph (whose brothers didn’t like his role as the baby, obviously)…
I’ve heard of twins separated only by minutes and it still affects them, one being “older” than the other.
And birth order affects parents. No two children really have the “same” parent. There are patterns in families. Count how many pictures are in the album of a first-born or only. Then ask someone three or four down the line how many photos there are of them without “everyone else in the picture too.” A firstborn or only has a time where their identity is formed as a singleton. Everyone else grows up as part of a group. That has profound effects.
Stereotypes exist for a reason.
Ask any teacher if they notice the difference birth order makes in their students.
Your role as the oldest was God’s plan for you. As a parent myself I found that book a useful reminder to not fall into certain patterns that might be less than helpful to my children. And it helped me to understand the dynamics and the normalness of the role siblings play in each other’s lives.