I took up regular coffee drinking when I was 8 years old. Maybe that's how I managed to get
through childhood without being diagnosed with attention deficit disorder. According to the diagnostic manual, you can't possibly have ADD unless you had it as a child.
The doctor's theory was that I avoided problems in childhood because I am "high functioning" and was able to compensate for the attention problems. Maybe so. Or maybe it was the coffee. Or maybe both.
When I got to college I did start to experience some significant problems because the style of teaching was very different.
Throughout grade school and high school, we spent a lot of class time interacting, discussing, exchanging ideas, etc. In college, I was expected to sit still for an entire hour and absorb all the info being thrown at me in a lecture. It didn't work for me. My grades plummeted. Then I took up smoking, and after that my grades improved.