A. Jerry's passage through the tunnel is symbolic of his passage into manhood.
In the short story "Through the Tunnel," by Doris Lessing, going into the dark tunnel represents a dangerous experience which demands considerable ability. As a consequence, because Jerry has seen other boys go through it, his decision to swim within the rock tunnel and accomplishing the challenge is a symbol of his coming-of-age.
both. an invention can only be realized through first, inspiration which gives one the idea to create and second the willpower and drive to get it done.