A diagnosis doesn’t magically turn a switch on, if a person is autistic, they have been all their lives, even if they never get diagnosed. What is this invalidating bullshit?
You’re correct, but so is the comment you’re replying to. Lack of a professional diagnosis does not make an autistic person neurotypical, but a self-diagnosis is not the same as a professional assessment.
People are absolutely horrid at objective self-evaluation. Even if someone’s making a sincere, good-faith effort to describe a set of problems they’re having (i.e., not to impress TikTok) and they arrive at “I’m autistic”, there are so many overlaps between disorders. Sure, you may have a lot of conditions that overlap autism, but are you sure the core reason is that you’re autistic and not that you have avoidant personality disorder, or OCD, or reactive attachment disorder, or social communication disorder, or sensory processing issues, or even lead poisoning, or sociopathy, or a learning disorder, or…?
It is correct to make a distinction between “I believe I’m autistic” and “I am autistic”. Self-diagnosis is potentially harmful in many ways, not the least of which being that the self-diagnosed person may have a different and treatable condition that goes untreated because of their self-diagnosis.