Who was Benn Gunn? How had he survived on the island for so long?

Ben Gunn provides comic relief in the island, a breath of fresh air in a very tense part of the book. A member of Flint's original crew, Ben Gunn was marooned on the island for three years and forced to survive on his own. Bem survives by killing and preserving goat meat and his obsession with finding Flint's treasure.