The Tears that Nobody Sees
In prison, everyone has to put up a front to show that they are strong in order to survive. Any weakness will attract predators. However, no matter how strong a person my seem when he's among his peers, once the lights are out and he's alone in his cell, tears often creep up to his tear ducts. Those are the tears that nobody sees.
Crying is a strength. I wish I could cry more.