What is the hardest form of poetry to write, and why?
I think if you really just setting out, then some forms are pretty forbidding, there are some verse structures that are quite rigid rhyming schemes, and so on. But you might find it pretty hard to say something original using those rhyme schemes, and it's probably pretty difficult to set out and write out a long, weighty, narrative poem of some sort or another, the way that some say the romantic poets did. That would be pretty hard to do, I'd say.