I took a trip to WDW in early 2016 and noticed via FB that somebody I went to law school with and worked with for a few years was also at WDW. We ended up meeting for dinner at Cosmic Rays. What's kind of sad and funny is that we probably live about 6 miles from each other, but hadn't met up for at least 6 months -- and then we just randomly crossed paths at Disney.
Second time it happened was last December. I was waiting for the monorail at GF and realized that I was standing behind a former neighbor of mine. That was pretty crazy.