Personally I wouldn't call autism an illness or a disease, but a disorder or disability or difference. And I think it might be pretty hard to convince someone who is ignorant :/. You're valid. I believe you.

Of you've tried to educate the person about autism and they still refuse, there's not much more you can do besides all them what it is about you that they don't understand. Think of it this way: if we could make everyone understand what everyone else is, this world would be extraordinarily different. It's our differences that make us individual but it's also what causes war. That's a big one to think through. Good luck with your person.

It depends on the person, usually I don't run into this problem because I usually only tell people who are close to me, and those people almost always believe. But when it comes to people who are strangers, I don't really bother to try to convince them, if they don't believe me it's probably because they aren't educated on autism and think all autistic people have to adhere to a stereotype. But when it comes to professionals (like therapists) I have to explain myself, my diagnosis, and how I personally deal with it.

I have learned that not everyone I can tell and I am comfortable with keeping it to myself but only disclose if it will help me grow or receive treatment

I don't. I don't have to do anything to prove that I am autistic to people that don't believe me./nm

With autism (late-diagnosed female who masked her whole life) and people give the whole, "But you don't seem autistic," bit, I usually tell them what I'm doing to mask right that second (I'm not making eye contact. I'm looking at your forehead. I'm not reacting as I would, I'm reacting the way you would expect someone to react. I'm not "quirky" I'm socially awkward masking as quirky because I know most people think quirky is a cute trait. Etc.)

Have a co worker like this .. I just ignore him..

I lost everything due to autism. Now I have to start over at 59 years old. Very overwhelming.

I gain and not lose

Thanks everyone for your input. Helps a lot. I just feel pushed in a corner sometimes with people saying things like I don't have "everything". I nwvervsaid I did. But my immediate family has been the worst even after getting diagnosed with a few things. They have never been supportive

I just lost someone I thought was going to be a really great friend… she said she couldn’t stand my “outbreaks” of autism… as if it was herpes or something. I told her that’s cool. I don’t feel like being discriminated against for something over which I have no control.