One of the issues I ran into repeatedly over the years in school was that many of my teachers would get very irritated with me for drawing in class while they talked. They seemed to take it as a sign of disrespect, as though if my hands were occupied, my ears stopped working.
What they could not grasp was that I actually processed their lectures better if I could doodle while I listened. If I was forced to sit still and stare at the teacher, I was distracted by every other little thing that went on in the classroom, outside the windows, or passing in the hallway.
While I was focused on sketching, I heard everything they said as if I were listening to it on the radio, but once my eyes got to darting around the room and out the windows, my focus was blown and I missed everything.
SOmewher in jr high or highschool, i started doing math equations or drawing. Not useful math either, I used a random number generator on my calculator to give me a string of 50 fractions (give or take, depended on the size of the paper) then I tried to reduce them to see if I could get a nice simple number from them... I got in trouble over it once or twice.