The feelings of parents for their children are the deepest and purest selfless great feelings, is not attached to any conditions. This feeling of yours is from the emotion of reluctance and attachment to your son leaving your side, and it is a deep love for your son. I hope you turn this emotion into encouragement for your son, inspire him to use the knowledge he has learned to continuously sharpen and improve himself in society, forge ahead, and will definitely succeed in proving his worth and become your pride.