It's Not Just Introversion
I'm going to take the test you linked but I answered yes to all the points and all the situations you brought up. Including being the weirdo in primary/middle school. I am your age btw, a year older.
'they rush to the worst assumptions, mistaking genuine confusion for sarcasm or defiance. The more we try to explain ourselves (which is not our strength), the deeper hole we dig for ourselves."
Example, but not for being confused, I was genuinely happy to hear it was break time when I was a cashier at a very busy grocery store at Xmas.
"Are you ready for your break?" I was asked.
I replied with a huge smile and what I assumed was a happy tone "Are you kidding me!?" 😃
I was brought to the office for a good whipping after break, for my rude attitude to my supervisor. 😳
As I tried to explain, I imagine just sounded like I was backpedaling and lying. How horrible. I went home and cried my eyes out.
"Taken to an extreme, one might even begin to dislike other people altogether."
Yep. Me now: GET OFF MY LAWN!!!! 😤
Makes me want to give you a hug. (Which I suppose might freak you out, so it's just as well I live on another continent.)