I lived for two years in Cameroon when I was a kid (around 4-5 years old), we were regularly spending time with another family who had kids and the same age.
Fast forward 15 years later, I’m 19 entering university in a totally new city in France. The first day every student is sitting in the amphitheater and they call the name of every student.
When they call the last name of the person close to me I recognize the name so I use it as an ice breaker to start a conversation saying that I knew a family with his name in Cameroon when I was a kid … He says that yeah he lived in Cameroon as a kid at the same time as I did, so here we go we found each other again 15 years later !