I used to wonder what was wrong with me – I knew something was wrong, but didn’t know what. I insisted on meeting with a neurologist – because I had developed some muscular ticks in my right face and neck. He told me what was wrong immediately – I was compulsive-obsessive. He could see the ticks in my face and neck – if he looked carefully, but assured me that no one else could see them – and I would just have to live with them. I could still be a productive member of society, he reassured me.
He then asked me what my profession was, and when I told him Technical Writer, this confirmed his diagnosis. And this was confirmed at my job – the wife of the owner of the business where I worked (it was a small company) said the same thing – good writers are picky (unnecessarily so) but this makes them good writers.
I am now taking a MOOC The English Grammar Boot Camp which deals with just this. It is a relief to know that some people are worse off than I am – they agonize over whether to use which or that.
Update: I just checked with Wikipedia, which I should have checked in the first place. Here it is called Obsessive–compulsive disorder (OCD) with excessive hand-washing being symptomatic. I prefered excessive tooth-brushing.