Most of my friends are ND in some way, even if it's "just" dyslexia (which can affect executive function not just literacy skills)
DS1 has a fine collection of diagnoses, autism being the most evident, but also dyspraxia, and I manage to make him look adept at sport. He also instinctively uses my coping strategies such as carry everything everyday to school in order not to forget things. I had wondered about dyspraxia for years, but the more I find out about late diagnosed ADHD in women, the more I wonder who wrote my biography. I also wonder what DS's consultant thought about my highly detailed mindmap on luridly coloured paper* that I took to the GP when I flagged my concerns about DS. I suspect it contained more information than the actual words of it.
*harder to lose than white paper
DS2 is "only" dyslexic, but he is so much like me and spends half the time on another planet.
There's a lot of relations I do wonder about on both sides of my family and I think DH is the one of the few males in his family who isn't autistic. He misses a lot of DS's traits because it is normal amongst so many family members, but it's the younger children getting diagnosed in recent years. He's a total geek but doesn't have the social/ communication issues of DS, DNs or his DBs.
Very obviously NT people often bamboozle me, especially those who are highly motivated to comform (and get it right rather than treading water to catch up on something unquantifiable that's missing. I like people who like what they like, and who know their stuff or try random things. All my close friends have been very invidual. About the one shared characteristic many of them have had is creativity.
And I have tripped the NDdar of various diagnosed ND friends.
I do think that if everyone around you is emerging as ND and they seem normal to you, that could be indicating something.
Likewise very NT people from very NT families with very NT friends probably don't do much in-depth crossing of patgs with ND people.