You must not know too much or be too precise or scientific about birds and trees and flowers and watercraft; a certain free-margin , or even vagueness - ignorance, credulity - helps your enjoyment of these things.
Adventure upon all the tickets in the lottery, and you lose for certain; and the greater the number of your tickets the nearer your approach to this certainty.
Comes over one an absolute necessity to move. And what is more, to move in some particular direction. A double necessity then: to get on the move, and to know whither.