A few weeks ago, a friend and I had one of those uncanny encounters, the kind that seems meant to be — even though it was actually the result of multiple variables co-occurring in a probabilistic manner. (Please see tinyurl.com/3pm7ypka for an additional perspective on this experience.) We were having lunch at the Walnut Cafe, discussing the current national and international situation, when my friend noticed that a woman at the next table kept glancing our way when we spoke. Our anxiety increased when this stranger approached our table. To our immediate relief — and eventual delight — she actually...