Paul,

As you now realize, Dennis left us 5 years ago after a long illness.  The Labs had a wonderful memorial that I was lucky enough to be able to participate.  The theme of the event was "Simply Genius."   My words are that he was a remarkable person and I'm so glad to have known him. 

BTW: I suspect your mistaking of the timing of his demise as being more recent would have made him smile.   Just as he did when he discussed Harvard never actually conferring his PhD due to a bureaucratic issue (a number of people have tried to get this corrected even after setting up a chair in honor but so far I do not believe the administration has relented).

Anyway - I agree that he was simply a genius.   We all lost a great man and magnificent human being when he left us, and I miss talking to him.

Clem