When I was in high school, my parents and I lived in southwestern Wisconsin near the Illinois border. One weekend afternoon we were driving along the historic Stagecoach Trail to Warren, Illinois to visit my stepfather's grandparents. The route of the Stagecoach Trail hasn't changed since it was established long ago, although it has been paved; it's a narrow country highway, old but well-maintained.
As we crested a hill I noticed a man walking toward us along the opposite shoulder, the direction from which oncoming traffic would approach. I saw that he wore weathered blue clothing, and he looked like he had been working (or even living) outside for an extended time. He was covered in yellow-gray dust--mostly on the front, as if he had been walking into a dust storm--and his brown hair fell past his collar and blew in the breeze. He looked exhausted, and didn't acknowledge our passing car in the slightest, it's like we weren't even there.
I glanced over at Mom, and her eyebrows were raised--I said "We should give that man a ride! He's so tired." Mom agreed, and we looked to my stepfather for his decision--he was irritated at what he thought was a ruse, and finally stated there had been no man, he had seen no one. The road was so narrow it would have been impossible for Dad to miss someone walking on the other side. Just to be sure, we turned around and in less than five minutes we returned to where we had seen the man; he was gone. There were hayfields nearby but they had been recently cut, and were no more than 6" high. There were no buildings the man could have reached on foot in so short a time. My stepfather maintains to this day that he saw no man, and my mother and I know we did.