You killed your "dear" father?... I guess he wasn't THAT dear

One of the most interesting poems was Edward by Anonymous.  I enjoyed reading the poem, mostly because of the way Edward's actions are revealed over the course of the poem.  The first line, "Why does your sword so drip with blood...(line 1)," pulls the reader into the scene.  Then the poem surprises the reader(or at least surprised me) with 2 small climaxes at lines 21 and 53.  He killed his father and wants his mother to bear the curse of hell from him.  Obviously he held some hatred against his parents.  The question is why?  The poem is very vague and illustrates no clear reason for Edward's actions.  He does hint that his mother has wronged him and his mother's reaction shows that she knew what Edward had done from the start.  I also was not sure why everything is repeated in the poem.  Overall, I really didn't get any deep understanding of the poem, but I still enjoyed it for what it is.