Thirty years ago today, I put on my best suit and set off for an interview for a graduate role in London. As it happened, I didn't get the job. I went home that evening and went to the eighteenth birthday party of a girl from our church who I knew a bit, at least partly because I was interested to know why I had been invited. Part of the answer appeared to be "to balance up the numbers of boys and girls". I happened to get talking to one of her friends as the evening continued. Just over two years later, we were engaged.