David has been blind from birth, but can see light. I imagine it would be like having a light globe over your head. Talking to David was often like talking to an adult, but he also had plenty of goofy teenager in him too. I would follow him to all of his GE classes:
In class we had to constantly talk to get things done, and we made the most of it with humor and generally enjoying the ride. I was not then, and probably never will be organizationally proficient enough to ever help David get good grades, but it was a great exercise for me, and we were able to share our knowledge of computers from our own perspectives, and generally build a nice friendship.