Childhood sickness and Attachment type

Maybe. I can relate to your post in that I had a much more functional childhood than many people on these boards, but I did spend the first 2 months in a NICU, and from what I hear they weren't great about pain management.

I do think health issues and the accompanying physical pain does affect the brain.

Also, we don't really know what happened the first 3 years of our life-- there are hidden unknowns.

And I think it goes beyond the first 2 or 3 years. Your later human relationships with siblings, friends, parents later in life, etc., are going to affect your attachment styles. There may be other factors that affect the sorts of people drawn to us lifelong too (ex: our social skills and communication skill and personalities and perceived attractiveness, etc.) and that can create reinforcing patterns.

I think some people may be more easily swayed (whether from brain structures, brain chemistry, or something along those lines) in a certain direction when it comes to attachment style, and so experiences that may not lead one person to be more AP/DA/FA could for a different person. That just makes sense to me-- everyon'e brain is not the same, and siblings raised similarly do not all end u with the same attachment style.

My last proper boyfriend, whom I lived with, had super parents... the best parents.
He was born with a cleft palette and no ear drums, so spent his early life in and out of hospital getting operations, and his fondest memories from that time were playing video games in the hospital

Guess what he does now?

Spends all his time playing video games if he isn't at work, and he was very, very avoidant with me, and with his parents... but not really with friends. Although, they claimed to me that he had phases of that with them too.

I say that but something hyper-abnormal about his family was that they all only talked about external things - things, tv shows, physical experiences, and never once did I hear them reveal anything that reflected how they felt about anything, or what they learned from anything... this is something he didn't like about me, I'm a very reflective and introspective person, and he found it annoying, but it's my best trait imo.

His parents are good wholesome people, longterm married with each other, and they raised someone who became a meth addict and who can't hold down relationships, and I also suspect he was emotionally cheating on me.

But I think the early hospital stays are what absolutely nailed the coffin on his attachment style, because it's the only way I can make sense of the way he became. He was very lost, I still think about him and hope that he's okay, I loved him very much.