How is this geeky and corny?

I got a new poster that has a picture of a UFO and says in the bottom "I WANT TO BELIEVE." I thought it was cool so I hung up on my room wall, but my roommate keeps laughing at it every time she looks at it; she says I'm such a dork and a geek. It almost reached a point where I'm really questioning if the poster makes me look like I'm a freak or a weirdo. How so?