Confusing me further, at this point the driver turned around, made eye contact and gave me a thumbs up. Then he began to speed up again. I followed suit, and as I did, it finally hit me what was happening: He was offering me to draft him!
Quickly I scanned the back of the tractor. A metal ledge and a pile of cut grass; no sharp edges to impale myself upon. This was crazy, but what the heck!
As he increased his speed, I followed suit and increased mine, so that the distance between us remained the same. I did not have my computer, but by feel alone I could tell I was traveling faster than I would on my own power. It was just like riding in a paceline, sort of.
Occasionally, the driver would turn around and give me a questioning nod, like "speed still okay?" And I would reply with a thumbs up.
Cruising along at what was probably 25mph on my folding bike, I spun madly in my high gear feeling little resistance. It was just like that scene in Breaking Away, sort of. I kept expecting him to stick his fingers out the window to challenge me to daredevil speeds - three fingers, four, five! Alas, the rickety farm vehicle was no more capable of such feats than I.
At the next roundabout, the tractor turned off and I rolled into town, beside myself with giddiness in the flickering sunshine. There are plenty of drafty mornings. But not quite like this one.