Knowing I was type C personality gave me a useful frame for understanding why I approach medical care the way I do. I trust doctors up to a point, but I’m not afraid to challenge them, and I need to see the data before I’m convinced a certain course of action is the right one. It’s always bothered me that doctors don’t have a patient-friendly reading list handy for any given condition or treatment. My first impulse when I want to know about anything is to read a book about it.