This quote is from the story, The Great Gatsby, by F. Scott Fitzgerald. It means that despite the struggles and obstacles life throws at people, they will keep on pushing forward. The image of boats against the current shows that it is a difficult and challenging journey, however, the past always catches up and washes back in, no matter how hard the effort of pushing forward. The past cannot be escaped and there is no avoiding it, but we can keep trying to move forward despite the barriers.