The Wife was at some Knitting & Spinning Event, Boy 1 was at a movie with his grandmother, and Boy 2 was asleep. I grabbed my depressing novel and a bottle of water and headed outside to enjoy the respite and bathe in the sun. I read for 10 or 15 minutes, then gave up, closed my eyes, and put my head back to enjoy the blistering but dry heat.

Beneath the chair, in the shade of a towel, my BlackBerry hummed. I picked it up to read the email that had come through, in case it was something dire from The Wife, and discovered that an acquaintance from my office had died last night, in an accident. No other information was forthcoming.

I had been back in the New York office only a few days earlier, and had passed this young man (he was 29) in the hallway, as you do when you're at work. Or at the mall. Or on the street. Or...anywhere. We didn't say hello to each other--both of us were busy and heading to some Desperately Important meeting or something.

I didn't really know him, but he seemed like a nice enough guy. We didn't work together, but we ended up in meetings together on occasion. He was a former marine, though he didn't look the part. But he had that calm stoicism, that centeredness.

And now, apparently, he is gone. I don't know why, or how.

I went immediately to the trite response of, "If only I had said hello to him in the hallway," as if I had some primal instinct for inanity and kitsch. If only I had...? Then what? Nothing.

People pass in and out of our lives for all sorts of reasons, and rarely with an announcement beforehand. What sends the chill up our spines isn't that we've lost someone so close, but that we barely knew the person at all--that we missed the opportunity to know that person, and now that opportunity is lost to us. And it is lost to us. And one hello in a hallway a week earlier wouldn't have changed that.

Obviously, you can't grab every casual acquaintance as they pass you by and say, "HEY. Let's go get some coffee. Tell me what's been going on lately. Tell me about YOU." Because a) who has time? and b) you'd be locked up by nightfall.

But I wonder...does that mean you have to let them all pass by?