Dear Guruji, when I am very sad, I write sad poems. Words gush out from somewhere. But when I am happy I am not able to do so. Can you tell me why?
When you are happy your consciousness expands and when you are sad it is more focused, it is in one place. That could be a reason.
When you are happy and not excited, but very calm and happy, then creativity comes up. If you are very excited then there is a buzz in the mind and there is an expansion too. When that feverishness comes down the happiness wells up and creativity comes along.