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.
I was chatting to one of the girls at my gym a few years ago and it turned out she'd just bought into AKL, pretty rare over here as we're in the UK so don't have the same volume as members as the US does.