This week I learned something kind of crazy that I never knew before.A gentleman came to my office complaining that five police officers had recently materialised at his front door, without warning or invitation, wanting to conduct a psychiatric assessment on him. It all sounded more than a little bit bizarre to me but, since the gentleman appeared otherwise quite lucid, I tried to dig a little deeper, in the hope of understanding what it may be all about. He didn't really know. The best he could tell me was the officers concerned were apparently attached to something called the Fixated Persons Unit.