 Why does Quest say he is lucky?
Trella feared she was in for trouble even before Motwick's head dropped forward on his arms in a drunken stupor. The dark man moved in on Trella again as Kregg overtook his quarry and swung a huge fist like a sledgehammer. The gravity of Ganymede was hardly more than that of Earth's moon, but the way the man picked up the limp Motwick with one hand and tossed him over a shoulder was startling: as though he lifted a feather pillow. But his ship was drawn into Jupiter and lost.” “It was drawn into Jupiter, but he landed it successfully,” said Quest. “If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever hear from him again?” she demanded.
 Quest considers himself lucky that he did not commit murder. He is not a murderer at heart.
 Quest considers himself lucky that Trella is in love with him.  Quest considers himself lucky that he is not actually an android.  Quest considers himself lucky that Asrange did not kill him.  Quest considers himself lucky that he did not commit murder. He is not a murderer at heart.