My daughter, who read at 4 and had those very important coloring in the lines and drawing skills that my son didn't have, was in a 3/4 grade class when she was a third grader. She did very well academically and socially and she really liked that year, but after that year she became bored with school and by middle school she just wasn't interested in academics, at least the way she was being taught at her school. She tells me now that she thinks she had ADD because she just couldn't keep her mind on the boring lessons in class.

But I remember daydreaming a lot in public school and it got me through the boredom. I couldn't understand why my daughter couldn't do what I did. I could tune in to the lesson enough to get what I needed and then tune out into my more interesting thoughts about something else.
I recently overheard a conversation between my son and daughter. They were talking about how I can look them straight in the eyes and make them think I am listening to every word, when in reality I am thinking about something totally different. When my son realized I was doing this several years ago he would sometimes quiz me to see if I was really listening. He used to tell me all about Yu-Gi-Oh and Pokemon and I just could not keep my mind on what he was telling me, but I could remember just enough to answer some of his questions correctly.