Every year brings its variety of upsets—some result in leaps forward, others in an impasse, and others in disaster. But let’s be clear, the difference between grace and disaster can balance on a fine point.

This year I needed a hip replacement. The one I’d used since birth was failing. I was a good candidate for surgery; healthy and active, with no diabetes, no hypertension, and no weight issues. Having spent about seven years in the operating room, I thoroughly discussed my procedure with the surgeon.

I entered the operating room, commenting on the back table set up with the nurses and technicians. I thought I was as prepared as possible. And I guess I was, up to that point.

I hadn’t counted on post-operative insomnia that hit me on the second night and almost every night for the next two weeks. I was a common disturbance to the dog and cat as they attempted to stalk the house peacefully. So there I was, stumping around the house at four AM.

It was summer, and I adopted a routine of getting several hours of sleep on the back porch starting at about five AM. Not even the cacophony of the birds disturbed this rest once it began. But I was up by eight, which was the end of sleep.

I was prepared for the hip replacement, but not for the incidental sleep disturbance that followed, and certainly not for the worry that I could be stuck in my new pattern of sleep disruption.

Luckily, my sleep returned to normal, and my hip healed, but I now place new value on what I had once taken for granted.