I'm completely incapable of writing a happy poem?

I have been told that I write amazing poetry and I have won many awards. But, just sitting here, I have discovered I'm completely incapable of writing a joyful poem. I have great ideas for poems but, they are all dark. I'm considered a very dark person in general but, I was just wondering why do you think I can't write a happy poem? Because of my personality? And when I mean dark, I mean prodigiously dark. I have been compared to Edger Allen Poe to many times in my life (even though to me that is one of the greatest honors)