My older brother (Dan) has severe Arnold Chiari and developmental issues. When Mom was pregnant, my parents were told he would never walk or talk, that he would be a human vegetable. They opted to keep him anyway.
27 years later and he is far from vegetable status. He has extremely poor eye hand coordination, his social skills are on par with a 11 year (that bit is my opinion; idk where he actually is), he has extreme nerve damage in his legs so he has no muscle mass to speak of. But he is extremely smart, especially when it comes to history and literature. It took him 8 years but he has a bachelor's in English. He hasn't been able to hold down a job longer than a few months, but my dad is a dairy farmer and my younger brother is taking it over when he's an adult so Dan will always have work he can get paid to do.
Growing up was interesting. My parents never explained why Dan was different but I was told many times that he was special; if I tried to wrestle with him, or make fun of him, or if we got into a fight, I got in trouble. I never understood that he was developmentally behind; I just assumed that he was fragile or something. My mom would often sit me down after Dan and I fought and tell me that he had a stint in his brain so fighting/wrestling with him could hurt him.
The truth is, he was favored a lot as a child and a lot of my needs were ignored to give priority to his. I had a lot of anger problems that my parents would dismiss as jealousy; I forced to see a psychologist after having a mental breakdown at 17 and was diagnosed with bipolar disorder. When I was 20, I was also diagnosed with ADHD, which both Dan and our older sister Kayla were diagnosed with in high school.
In school, I had to defend him pretty frequently from bullies. He was 3 grades above me so that usually happened on the school bus. I won't go into details, but let's just say that kids are horrible, horrible monsters and I got in trouble daily.
My mom recently confessed to me that she never realized she was over looking me. She showed me some pictures of me and Dan growing up and a lot of them show him doing shit like dangling toys in front of my face while I was strapped into a high chair or pulling my hair while I was crying. Getting away with being a little shit.
I don't hold any grudges over my childhood. When I was an angsty teenager, I would mope around like I was some sort of victim but the reality of the situation is my parents were doing the best they could with what they were given. My parents don't love me any more or any less than my siblings. I have troubles seeing Dan as anything other than a normal guy. My parents still get mad at me when I shut him down for doing/saying something stupid or inappropriate; they say I'm being mean, I say I'm playing the role of annoying little sister.