For me (recently diagnosed on the NHS age 37, the wait was 9m) it became very apparent when my daughter was diagnosed aged 3 two years ago and I stated to go on courses to learn about autism so that I could help her.
She is 'high functioning' (not a used term anymore but seems to best explain her). She's highly intelligent, advanced even academically. She was a very late speaker but once it came it came in paragraphs. Most people don't realise she's autistic because even at age 5 (nearly 6) she masks so well but she has full time 1-1 support in the form of her own TA at school under an EHCP because she just cannot cope at school without it.
Seeing her and the things she struggles with ticked a lot of boxes for me reminding me of how I was as a child. She is basically like me, except in the 90s when I was at primary school I was just thought of as naughty, over opinionated, awkward and weird.
Then when I stated to do the courses and I learned more about autism generally - and about the stereotypes and how women and girls often don't fit them it was like 'ping! That's me!' Every five minutes.
So I'm now diagnosed, and am also on the pathway for an ADHD assessment too which I am convinced I also have/am.
For me a diagnosis has been a revelation. It's allowed me to say no to things, make changes, start - for the first time in my life - to stop suppressing my needs (not quirks, not wants, not preferences, needs) to keep other people happy. It's given DH a level of understanding as to why I find some things really really difficult that other people don't even think about. With that understanding he's able to be more accommodating- instead of thinking I'm awkward.
Awkward has been the overriding description of my for 37 years. No more.
I am a mum of two, carer to one, a wife. I had a successful career pre children, we own our home, we're financially stable and happy. I've got friends - not many, Ive always kept a small group though. I've managed all that being an undiagnosed autistic person wibbling my way through. I feel like with my new knowledge and understanding I can be better, happier, more settled.