My dad runs into people he knows everywhere. Just as an example, he once saw an uncle he had not seen in 30 years in a restaurant in Lubbock, TX. The uncle was travelling from his home in Montana to visit his daughter in Florida.
The best story happened a few weeks after my daughter was born in 1992. My mom had come out to help when I went back to work. My dad owned a gas station in a town 6 hours away from our home. On Friday afternoon, a couple they know stopped to get gas, and mentioned they were headed for my town to see their kids for the weekend. My dad jokingly said, "For 2 cents, I'd throw a bag in and go with you." They told him to go pack, so he did.
Several hours down the road, they stopped to eat. The husband went to the restroom, and my dad was sitting talking to the wife, when some friends from their church walked in. They kept giving my dad weird looks, until the husband came out of the restroom and sat down. It wasn't until Dad saw the look of relief on their faces, that he realized what they were thinking!