The steadiest speaker, when before the public, often breaks into a perspiration, as if he had wearied or over-heated himself; some tremble in the knees when they rise to speak; I know of some whose teeth chatter, whose tongues falter, whose lips quiver. Training and experience can never shake off this habit; nature exerts her own power and through such a weakness makes her presence known even to the strongest.
Lucius Seneca, about 2000 years ago. The fear of public speaking has been with us for a while.