On 2014-01-09 05:32:44 +0000, Wayne Boatwright said:

> I really do try to explain or answer questions when I feel qualified
> to do so. Obviously, sometimes it doesn't work. Perhaps I'm not
> stating it in terms that make sense to you.

Adding "duh" to imply the person you're speaking to is stupid, isn't
helpful changes the "sense" in which the information is proffered.
Maybe you didn't know that.