Tribes 1 Legendz

How can a person this stupid operate a computer?

Could be several reasons. It is possible she never had a very good education. What is her age? Young children ask questions like this all the time. She realizes that gravity pulls things down, and in her mind down means from top to bottom, not from outward towards the center. Her premise was well, if gravity pulls things down, how can water at the bottom of the earth stay there. Basically she just made a slight error in her premise. I wouldn't call her stupid though, just ignorant.