Knowledge Created Out of Need. I was with two other people that I knew, a man and a woman. The woman was demonstrating something about her trousers to the man and with her left hand she was pulling at the left pocket of her trousers, pulling it away from her body. At the same time she was moving her right hand in and out of her right pocket and wanted us to notice how the fabric of the trousers didn't seem to move at all, even though she was doing it simultaneously with pulling at the left pocket. One seemed to have no effect on the other. I turned to the man and said, you know what they say, knowledge is created out of need.