Since everyone with Autism has different symptoms, how do you know that they are faking it

Not everyone with autism has one special interest, some have incredible low IQ.
I once remember someone with serve autism in high school, and one of my "mates" used to say he just pretends to be autistic to get attention. I used to think bigotry like this was unacceptable and people with disabilities would be more sympathetic - I guess not.
And finally - trust me, no one wants to be autistic, since when to you here Mark Zuckenberg being cooler than Tom Cruise - I've never heard anyone say this. I guess people who do pretend on purpose must be crazy.
I will also add, what cash benefits do you get? You would have to fake a pretty severe case to get anything if your lucky. And finally instead of personal stories, where is the evidence and statistics for this happening?
i agree that its unlikely anyone is faking autism.
most disability pretenders like katy perry ans russell brand do it as a sexual thing usually in private and dont want attention