Initially after being chosen as Dragon Warrior by Master Oogway, that was a huge task to teach Poo the Kung-fu. At first it seems impossible.As poo doesn’t know a single move of it. He was so slouchy all the time. And loves food only.
His mentor, Master Shifu observed that food makes panda most active, he can try above his limits to eat his favourite things. Then he teach Kung Fu to poo through a different manner. Master Shifu used this piece of wisdom on in his training with Po by promising all kinds of food if he manages to finish his training.
The main job of Teacher or mentor is to find the way to motivate his students. Master Shifu is the perfect example of the value of a teacher or mentor in our lives.