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.
For me, it was really only to know and also to have that when it comes time to talk to my youngest about it (fast approaching…). But the learning I have been doing for a while, so the diagnostic makes no difference, really. Oh wait, there was one interesting bit, doing an IQ test again to see what difference 30 years make from the first one I took (when I was trying to understand why the hell I was so “weird”, but it led nowhere back then).