My brother, like me, is neurodivergent, but has had a bit more success in life than me, so I look up to him. And he understands me better than anyone else and tells me the same about him. It's nice to get an affirmation of my worth as a person and acceptance by someone while surrounded by and living with people who really don't get it.
Nothing else to say on it, really. We had enchiladas and beers and just chatted about how much work sucks. It was fun. I feel good for once.
Sibling relationships can be really wonderful, once you reach adulthood.