If your poetry is incomprehensible, it's difficult to understand, and it might be impossible to explain. Could be you're a genius! Could be you're just not very good at poetry.
Incomprehensible originates from the Latin incomprehensibilis: in- ("not") and comprehensibilis ("perceptible, evident, intelligible"). Many unfamiliar customs or rituals seem incomprehensible from a distance, for example, the early Chinese practice of foot binding, in which girls tightly bandaged their feet to prevent them from getting bigger. Similarly, future generations may find today's Western high-heeled shoes incomprehensible, leading them to ask, "What in the world were they thinking?!"