In the early part of the war, he was beaten back and much of his army had deserted him. The British Aristocracy scoffed, smirked at his abilities, his reputation and his ‘place’. He used that underestimation of him to his advantage.
That always happens in daily conversation during a war, but I doubt that was their 30 year history of the man.
Washington was a very large figure, not an unknown during his pre General life.