Why does Schindler drop the ring?

Schindler drops the ring because he is so moved by the gesture.... and is deeply saddened by the fact that he didn't do more. On the ring is inscribed a Talmud expression: "Whoever saves one life saves the world entire." When leaving, he grabs Stern's hands and whispers to him that he could have gotten more Jews out of Plaszow. Stern shakes his head and tells him that there are 1,100 people alive because of him. Schindler gets upset, realizing that if he had just sold his pin or his car, that he could've saved more lives. His Jewish workers comfort him by surrounding him and embracing him. The workers watch as Schindler's car exits through the factory gates.

They give him a gold ring. Many of these people have been imprisoned for years, and they give him a gold ring, something that could have been used to save many more people. Where did they get the gold to make the ring? Think about it. Would that not stagger you, you who is now looking back you could have sold your pin or your car to save a few more? Good God I don't think I could have ever gotten up from the ground after I had been gifted something so heavy.