Struggling a lot with this at the moment - I was formally diagnosed only a couple of weeks ago at age 45 (I decided not to ever mention it prior to that, as I felt the need to have some kind of "facts" to back up what I thought I already knew.)
What frustrates me the most is the disbelief of friends who I have known in some cases for decades. They know that I have never had any romantic relationships in my life; saw me abuse myself with alcohol and drugs when I was a young man; have seen me melt down and disappear into the night when social/sensory situations have overwhelmed me; have openly criticised me for being "immature", "irrational" and "frustrating to deal with" etc. I have even unknowingly described my autistic traits to them quite explicitly in the past; "I'm not stupid, but I am slow"; "No, I don't understand this context that you expect me to intuit"; "I don't have a 'gut feeling' about this"; "I've tried 'just being myself', but that never seems to work out", "What do you mean 'she's interested in me'? How could you tell?".
Now that I can finally begin to explain these troublesome events in my life, all of a sudden people seem to behave as if an explanation for these things is no longer required. As far as I can tell, this is just because they can't face the intellectual 'burden' of trying to understand something that can't just be explained in a 'sound-bite' over a pint of beer.
Despite being diagnosed through a lengthy assessment, involving multiple professionals, all specialising in ASD, I just keep hearing that I'm "Just a bit quirky." (I have really come to loathe the word "quirky" - I find it incredibly dismissive)
Phew - sorry about that, rant over!!
_________________
When you are fighting an invisible monster, first throw a bucket of paint over it.