A very interesting question. I too would like to know how many 30+ members of WP were diagnosed/ self-diagnosed/found out about aspergers, autism, neurodivergency etc before becoming an adult.
I get the impression that 30 is the age at which one is pretty much set for life, at which having missed, or been able to use, the "normal"/NT opportunities for career development in particular, determines to a huge extent what is still open to one.
And if one has never heard of, or not identified with, nor been diagnosed as Aspergers/Autist, it is unlikely that someone would see any reason to ask for help, request accommodations/support to deal with the things that NTs find relatively easy but we find so hard, and which make it very difficult to progress academically/professionally however "intelligent"/gifted one is.
I am 46, found out about aspergers two and a half years ago, and self-diagnosed soon after. I had thought I "was" various things before that, none of which helped me really understand my problems, nor how to handle work, academia, etc ( eg. according to my parents I was lazy, selfish, greedy, contrary/defiant, untrustworthy, inconsiderate, deliberately and repeatedly immature; according to teachers of art and english a very imaginative, creative daydreamer, and generally, at school/uni a persistent underachiever, who "could do better".
I wonder what difference it makes to someone, what difference it has made, to people around/over 30, who were dx'd, or self-diagnosed, before they became adults. Did it help?