One of the reasons this works so well is that it associates the memory of a social interaction with the definition of a new word. Memories are easier to remember than definitions, and this association allows you to use the memory as a retrieval cue for the definition. There are words that I learned years ago and still remember, not because I memorized the definition, but because I remember the conversation I had with one of my friends.
How to Expand Your Vocabulary
David J Pfeiffer

Same here. I love doing this.