As a late-diagnosed AuDHD (diagnosed at 31, about 2 years ago now), I still 'struggle' with my identity of being on the spectrum. I have zero doubts but the natural reaction of everyone in my life upon hearing it has been some variation of "no way, I've known you your whole life, you're totally normal" even though these same people have been the ones I compare myself to when I always felt there was something "wrong" or "different" about me.
Now that I know more about myself through the lens of being on the spectrum, so many things make so much more sense and yet at the same time everything feels exactly the same. I'm still the same person I saw myself as before my diagnosis, I simply have a much greater understanding of why I am that way and what makes me tick.
It's a constantly ongoing process -- Our different-ness is always expressing itself in different ways as it clashes with allistic expectations and norms, and that results in a constant journey of self-reflection and new understanding.