That answer tells me you don't, in fact understand modern sports psychology but are a talented BSer.
Today sports psychology looks at both extrinsic and intrinsic motivators. Extrinsic (outside) motivators are external rewards, such as trophies, money, medals or social recognition. Intrinsic(inside) motivators arise from within, such as a personal desire to win or the sense of pride that comes from performing a skill. Attention focus is another area of psychology that plays a great role in sports. The ability to tune out distractions, such as a crowd of screaming fans, and focus attention on the task at hand. "We define ourselves" addresses the effects that negative outside voices may have on the psyche but it does little to counter effects of the psyche when outside voices are giving positive feedback. You were correct in saying the team does not need to listen to outside voices but unfortunately the need to do so has little to do with the human psyche doing it none the less.