Ask someone with Asperger's syndrome.

[GrandizerII]

I don't really understand what this autism thing is tbf because I was kind of an introvert, shy, kind of guy that  got bullied but after some time I did some self reflection and figured out where I was lacking and rectified it. My doubt is, since you know all your problems so clearly, can't you do the same thing? Or is it like mentally impossible for you or do you lack motivation?

You were kind of shy and an introvert, was it anything more than that? Autism spectrum disorder is not primarily an anxiety disorder or verbal communication disorder. It is a pervasive [neuro]developmental disorder that doesn't just simply go away with life experience and opportunity to thrive in society, and it manifests in different ways in people with autism (just as there are all sorts of types [personality, intellectual, etc.] among neurotypical people). Expecting people with autism to rectify their struggles with this condition is like expecting a man with damaged legs who can't walk as a result to just get up and walk, no problem. It doesn't work that way, and if that had been the case, I would not have been still struggling with socialization, considering I've put in a lot of time and effort into becoming a better person socially. So perhaps not mentally impossible, but it's definitely extremely challenging for people like me to stop having this condition.

FTR, one need not be an introvert or shy to be diagnosable with autism. There is such a thing as an extroverted person with autism, believe it or not.

Also, if indeed you do have autism, then perhaps you're of the really high functioning type whose condition isn't as bad as mine (high functioning though I may be). Or you're like my brothers, who used to be really shy when they were younger but were still nevertheless neurotypical. I don't know you from Adam, but anything is possible.