For the next 17 years, Cowboy’s Jazzy Wonder (“JW” hereafter) and I rode Indiana corn fields and forests, then Texas pastures and woods together. He taught me to be a much better rider, and I taught him that, when I was on his back, he didn’t need to worry. Don’t get me wrong – he was not a panicky horse, he was just reluctant to do new things. Eventually, though, he understood that if I was aboard, I wouldn’t lead him to anything he couldn’t (or shouldn’t) do. I had a code word for this: “cohomology.” I told him early on that, as a mathematician, I knew what that meant but he didn’t. As far as he knew, it might be important in deciding whether something was OK to attempt or not, so, since he didn’t know what it meant, he should just listen to what I wanted. (Aside to the reader: cohomology has nothing whatsoever to do with anything we were doing, but, as I explained to him, he didn’t know that).

He was always a terrific horse with an inexperienced rider: most horses, if they are confused by what a new rider is cuing them to do, will become agitated and panic, causing a dangerous situation. JW’s consistent response to this sort of thing was simply to stop and look around for something to eat. Irritating, perhaps, but not dangerous. This led him to be the mount of choice for many, many children and novice adults visiting us.

An experienced rider, however, would usually find him a pleasant (if somewhat lazy) mount. On the other hand, for me, he would do anything. The only limit was whether or not I could figure out how to make it clear to him what I wanted to do. In some of the big, open cornfields of Indiana, I found out that actually he could really run (and enjoyed it). He needed a large space to be comfortable opening up, but he truly had a spectacular top speed. When we had enough room to run, I didn’t usually have to remind him about cohomology, but if we were crossing water or bridges or logs across trails, I might need to do so. Just a reminder was enough.

As he got older, his knees became arthritic, gradually degenerating to the point that he was in constant pain, despite the best treatments modern veterinary medicine has available. I hadn’t ridden him in some time, but it became clear that even walking around to eat and drink was horrifically painful for him. The only reason I was hesitating to do what needed to be done was that, selfishly, I knew how much I would miss my partner and friend. One morning, after his spending the night in his favorite pasture and seeing the sun rise from the highest point on our property, he started a slow, painful walk back toward the barn for breakfast. I had to lead him through a circuitous but fairly level path through the woods because the slightest downhill grade had become excruciating for him. As I got back to the barn with him, I knew that he couldn’t make that trip again, so I made the call that needed to be made.

Later that day, he managed to hobble to near where we needed him to stand, and as the vet needed him to take one more step forward to be positioned safely, I whispered into his ear, “Good-bye, old friend. Cohomology.” And he took the step.