A competent and self-confident person is incapable of jealousy in anything. Jealousy is invariably a symptom of neurotic insecurity.

More from Robert Heinlein

• A brute kills for pleasure. A fool kills from hate.
• A committee is a lifeform with six or more legs and no brain.
• A fake fortune teller can be tolerated. But an authentic soothsayer should be shot on sight. Cassandra did not get half the kicking around she deserved.
• A generation which ignores history has no past and no future.
• Always listen to experts. They’ll tell you what can’t be done, and why. Then do it.
• Always tell her she is beautiful, especially if she is not.