I'm sorry your wife withheld such important information about your son, and for so many years. That kind of retrospective discovery can feel horribly angering and frustrating, because there's not much you can do about the time you were missing this info. Best you can do now is to go forward knowing what you now know.
It's also pretty asinine, if you don't mind my saying that, when anyone says someone "can't have" Asperger's because they "have too many friends," or other similar inanities they believe couldn't possibly be the case for someone on the spectrum. I'm not yet diagnosed but I'm 99% certain I'm on the spectrum, yet there is someone in my life who is being not just doubtful but downright rude and offensive in telling me I "can't be." And for similarly inane reasons too, such as that I can actually come across as social and "normal" -- yet he doesn't see what it costs me later on when I collapse at home.
Try to brush aside your ex-wife's poor choices and views, mentally within yourself, and focus now on seeing your son now from a new position in which you can understand him even better.
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