You can measure your personal success by how well you are able to do the thing you set out to do. All creative endeavors are highly subjective, and there aren’t any hard and fast rules on what you should and should not do. However, if you intended to create a rock song about gardening, and it ends up sounding like a hip-hop song about volcanoes, then you didn’t accomplish what you intended. It’s time to go back to the drawing board and revise how you create your music.