My husband who was in military intelligence years ago once told me that it wasn't just the training that made them successful but the fact that they trained in chaos. I think the ability to function well and improvise when things can't be planned is a trait that my son is developing while dealing with his invisible disabilities. Before he started getting frequent migraines, he competed in a spelling bee at the state level and seemed to enjoy spending hundreds of hours preparing for that. Chronic pain has slowed him down but I predict that his grit and determination will help him overcome the disabilities.
I talked to my uncle, a retired engineer, about how he managed to become an engineer when he had bad headaches and a difficult childhood. My uncle had to work to help support the family in high school, but he taught himself a lot of what he needed to know after work and school. His small town school didn't offer the higher level classes that he needed but he found that he could teach himself a lot of what he needed using library books. I got some unexpected encouragement for continuing homeschooling.
My stepson is highly gifted. I used to think high IQ alone was enough to predict success but my stepson does not seem to have the other necessary traits for success that the article mentions and he is barely able to support himself. I wish I knew how to help him.
My daughter, who was never tested but possibly moderately gifted, would definitely score highly on a test for social giftedness. It is the social giftedness that makes her very successful in sales. She is a very fast learner and made higher scores on tests than the people she was training with who happened to have marketing degrees. She does not have a degree, but she is planning to go back to college to get one. She is close to earning more money than my husband who has a degree and a job as a supervisor and retirement income.