I can understand what you feel. Because, I too had the same query. While responding to some forum question or article, I realize that, I have some deep thought about the topic and I really wanted to do an article on the same. On the other hand, I would have already given my valid points on that topic in forum itself, So, I get to think about it again, whether it would be considered right or just denied for reproducing the content. But somehow I learnt to give answers in ask expert or in forum according to the question. When it comes to writing article about it, I do read many other related articles and sites, gain some more knowledge about it, and then refresh my ideas. Then automatically, you will some more content or different thought to write about the same.