I can relate, Bri!
I've always been fascinated by birth order, probably because there was an article about it in my Dynamite! magazine.

Recently I checked a book out of the public library on the subject.
My older brother is a year and a half older than I am. My younger brother is 8 years younger. I am the only girl, and was born on my dad's birthday.
So I look at who "I" am and I think it was shaped by birth order/only girl status. At once a bit spoiled (girl) yet fiercely independent, I'm all sorts of extremes.
As most of you know, I'm very close with my family. We adored my younger brother from the second he was born, still do. My older brother and I are very very close. He is my rock. He is so obviously the oldest: the one you can count on, the one you can lean on. He had struggles but he has always been a winner.
My younger brother is amazing: he's always seemed so self-assured, and he's so likeable.
So, too, I compare. I will always think myself as different from my brothers (besides the obvious ways): plagued by a dichotomous mind. They seem more at ease with who they are.
I wouldn't trade a minute of any of it.
(side note: my mom lost two babies, both boys. One would have been older, one younger. Still would have been the only girl/middle child.)