You don't fundamentally change, you are still you, even if you are older. It's the same you, you just need to survive in the adult world. You don't gain adult powers, you just have to do adult things.
Madness string 95080
There aren't a ton of great autism orgs out there. The one I know of that isn't awful is the Autistic Self Advocacy Network (ASAN), and they have recently had some concerns come to light involving internal racism and bad management. I can tell you to put a country mile between you and Autism Speaks (anything branded with puzzle pieces typically ties back to them). They are the PETA of autism advocacy.