My husband, who is in his late 50's, did well on tests even though he never studied in high school. He didn't have time to study because he was working so he could have enough to eat. He was one of eight kids in the family who had to take care of themselves after their mother died. Hid dad wasn't around much. There was no one to encourage him to do well in school, not even his teachers, because he was from the wrong side of the tracks. Nobody was making sure he wore clean clothes to school or cared if he had clothes that fit or if he had enough to eat or was getting the proper nutrition.
He made it on his own because he had that innate ability to learn quickly, had good people skills, and his survival instincts were good. He made high scores on tests in the military even though he hadn't had the best education, high enough that they put him in the Army Security Agency, which Wikipedia says was comprised primarily of soldiers with the very highest scores on army intelligence tests.
My husband told me a few days ago that he never felt like he needed to have everything planned out like I do so he doesn't have anxiety over the possibility of things going wrong and needing to have a contingency plan in place. He always knew he could "muddle through" whatever he needed to get through. I can see that there were some good things that came from his difficult childhood.
But I still worry about my twice exceptional son. I think it is harder for a twice exceptional child to muddle through, especially when it seems like so many people don't understand that a child can be gifted and also have a disability.