When they took a young man into Tellson's London house, they hid him somewhere till he was old. They kept him in a dark place, like a cheese, until he had the full Tellson flavour and blue-mould upon him. Then only was he permitted to be seen, spectacularly poring over large books, and casting his breeches and gaiters into the general weight of the establishment.
But the fact that some geniuses were laughed at does not imply that all who are laughed at are geniuses. They laughed at Columbus, they laughed at Fulton, they laughed at the Wright Brothers. But they also laughed at Bozo the Clown.