In my case something that happens sometimes: Meet someone new, usually the very high social skill kind that can charm anyone into instantly feeling they're their best friend, and have a long, stimulating conversation. A few days later I've forgotten all about it.

A year later, someone I've never met before (right?) hails me and knows all about me. Super awkward. Because they remember it all, effortlessly. Whereas I, social dues paid, forgot all about it again.