Is It Something About Me?

One of my co-workers, who I don't know well...or even like (it's the eyes! He has sad puppy eyes! I have trouble liking someone who walks around all day with an expression that says "pity me!") approached me and starting quoting Serenity lines. Randomly. I didn't provoke it. I didn't say, "Hey, watched an sci-fi movies as of late?" Then he asked to borrow my Firefly DVDs.

I don't know this guy well. I don't consider him a friend. Can he be trusted with my beloved DVDs?

Apparently his dad is in bad health. That fact, combimed with the reality that the excuse "I need to watch those DVDs everyday, all day, until the end of time" just wouldn't work, caused me to bring in the DVDs as a surprise for him.

But, I'm rambling away from the big question. I have never talked about my love of Joss Whedon in front of this guy or anyone who talks to him. This wasn't a random conversation on his part. How did he know I was a Firefly girl?