I had a letter land on my office desk one morning. It only had a personal card in it with her name, her mobile phone number, and her email address on it. I had only spoken to her once before, and that was outside a school as she'd dropped her kids off at first year. That was at least five years ago, and we’d only exchanged the briefest of pleasantries. I’d seen her before then, and since, on an occasional basis, driving h...