Why couldn't I have known this while he was alive?

So, my father and uncle told me this remarkable story about my grandfather.  This story that is so badass that I wish I had known about this before he died.  I would have talked to him at length about this and probably recorded it somehow.   Back when he was maybe twenty or so, he was hitchhiking from Mississippi to New Mexico for a job, probably on a farm or something of that nature.   A man pulls up in a car with his wife behind him in another car.   He asked if my grandfather would drive that car so he could ride with his wife in the other car.   That sounded reasonable, so they both drove off down the road for a short time, maybe a few hours or so.  

Eventually, they got to the place where the husband and wife needed to go north.   My grandfather got out of the car, the couple each took a car again and drove off.   My grandfather didn't think anything of it.    After a few days passes by, he sees the car he drove and the couple on the front of the local newspaper.