I smile a lot at children, a professional habit carried over into a character trait. The smile goes something like this: first catching the eye of the child, who is usually watchful and cautious, then a broad smile with lips closed, followed very closely by a widening of the eyes and then perhaps a wiggle of the eyebrows. This is often enough to make a child smile back, although I'm painfully aware that some children will be quite worried by a stranger smiling at them, and some will regard it as a false gesture—nothing more than a professional quirk with no underlying feeling.

When not at work and wandering around the supermarket or down the high street, I often look at children because, for one thing, it is good to see them behaving naturally outside of a hospital setting. When they catch my eye I find myself responding with my professional smile, at which point, if I …