I always knew I was different, but it was only at 33 that someone suggested I might have it (I was getting myself checked out after my father passed), so I talked to a doctor about it a couple of times but never truly did all the tests.
It took me having both kids diagnosed to go through the entire process to get my diagnosis (same as the kids, unsurprisingly), and I cannot avoid cursing myself at 33 for not doing it sooner. Everything I learned in the 10+ years between both things could have made that period a bit smoother, using all the tools and techniques I have acquired since.
I only sought and received a formal diagnosis last year, despite being aware that I met the DSM V criteria for over 15 years prior. I had toyed with the idea over the years, but only pursued it last year for health reasons. Getting a diagnosis meant that I had a few more levers to pull with my employment.