Ego is the Latin word for "I." So if a person seems to begin every sentence with "I", it's sometimes a sign of a big ego. It was the psychologist Sigmund Freud (well, actually his original translator) who put ego into the popular vocabulary, but what he meant by the word is complex, so only other psychologists really use it in the Freudian sense. The rest of us generally use ego simply to mean one's sense of self-worth, whether exaggerated or not. When used in the "exaggerated" sense, ego is almost the same thing as conceit. Meeting a superstar athlete without a trace of this kind of ego would be a most refreshing experience. But having a reasonable sense of your own worth is no sin. Life's little everyday victories are good—in fact, necessary—for a healthy ego.