A couple weeks ago, I was hanging out with a friend, and trying to get wireless to work on both our laptops. This friend is not in a tech-related field, and doesn't spend much time in front of the computer.
Me: "Can you try to access the internet?"
Him: [opens a browser at his laptop]
Me: "You use firefox?" [overjoyed]
Him: "Yeah... why?"
Me: "That's great! So do I! I'm so excited!"
Him: "I don't understand."
Me: "It's, um, it's like if we both really liked the same movie."
Him: "Oh... [deep look of understanding] Well, I just like firefox much better than safari."
Me: "Oh right, this is a Mac. Firefox is the only reasonable choice." [greatly disappointed]