Tourettes is a horrible thing to suffer. My son has it very mildly. His tics are awful sometimes but he needs to be stressed-free for them to be calmer. He also makes sounds but it's not very bad these days. It's true about obsessions or compulsions because as a child he had so many different obsessions like collecting things. I can imagine Johnson not wanting to give up and wanting to get it right. So the tourettes in him would make him like this. I can't believe it existed in people back then.
You wrote a wonderful and interesting story about Johnson. I am glad you passed your exam.