Just because you are good at a video game simulation doesn't mean you won't suck in real life. The expression comes from when Conan O'Brien challenged Serena Williams to a tennis match - then kicked her video-rendered ass on Wii Tennis.
Despite his l33t0r skillz on the "America's Army" FPS, Pvt. Hicks turned out to be an absolute klutz after he enlisted. He was a victim of the O'Brien Effect.
by robotiki March 02, 2010