From Redditor u/Scared-Huckleberry64:
I had a best friend who I went to kindergarten with. He had an older brother the same age as my older brother, and they would get into fights all the time. Their family lived a couple houses away from ours. For reasons unknown, they abruptly moved away halfway through the school year and we never saw or heard from them again. Take note that I had a specific nickname at this time in my life.
About 14 years later, I was at a friend's apartment one night, hanging out with a few people. Some friends of theirs came over to join us, and this guy walked in who looked really familiar. I thought it could be my long-lost friend, but I didn't say anything. Turns out his name was the same. I still didn't say anything. Take note that no one in the room knew my nickname from way back when.
After a while, he points at me and asks if my name is (said nickname.) It had to be him! I said yes and asked if he used to go to the aforementioned school. He said no.
I asked him if he had an older brother. He said no.
We had a long, strange conversation weeding out facts from non-facts that we remembered about each other. He remembered me, but I had a ton of (apparently) incorrect memories about him. But he was the same kid.
The next day, I interrogated my whole family about everything they remembered about his family and all our information was the same across the board. The school, the town we lived in, the brother, etc.
Years later, my husband catches me off guard with the fruit of the loom Mandela effect (I definitely remember the horned basket!) and this is how I was introduced to this phenomenon. I told him about my former friend, and he told me that's probably my Mandela effect experience.