For 2 weeks, my new puppy would just follow me around but would not react to any of the names I came up with. One night, I was sitting on the sofa watching Start Trek Voyager and Janeway said "Seven of Nine" and my dog's ears shot up. After about 20 minutes, I kept noticing that every time Seven of Nine was on screen, his ears were up.

He IS a boy dog, but I didn't think he was that male, so I left him on the sofa, walked out of the room and said "Seven!" and he came trotting in with his ears up. And that's how he got his name.