I'll accept your own experience, and am happy for you. As for how Mr. Norvig's coping -- let's wait for him to post his own.
I could see a language designer (say someone like Guy Steele) who has made major contributions in Lisp happily moving on to his or her next research interest, pursuing a completely new design. Those of us stuck in the "real world" of trying to make a living with our software skills are a different matter.
In my experience, once having worked with Lisp I found it extremely difficult to switch to programming in Java. I spent a lot of time trying to make Java look like Lisp, which in my opinion made my code more readable, but to other programmers I worked with - not so much.
My point is, Lisp can be a mind altering experience, much like LSD (I suppose). Some have the ability to compartmentalize the experience and move on with other pursuits and some are forever hooked on the "forbitten" fruit.
I think it depends on your trajectory. I did BASIC then 6502 assembly language then C. Then a few other languages before spending considerable time in Lisp/Scheme, and then Haskell.
Much like the author of the posting, I find some elegance in Lisp, but I've never been comfortable with it. While I can code anything I've ever felt the need to do with it, it would rarely be my first choice language. And especially with respect to performance -- I find myself having to spend a lot more time at the whiteboard ensuring that what I'm doing isn't too computationally expensive with Lisp. I just don't have nearly the same sense of cost with it.
Agreed with your last point. I have read about people who loved Lisp so much, that they wrote Lisp to write programs in other languages for them. Two cases:
* http://www.merl.com/papers/TR93-17/ (Lisp to Pascal)
* Erik Naggum told of his dissatisfaction with C++, and wrote Lisp to do his job for him.
I could see a language designer (say someone like Guy Steele) who has made major contributions in Lisp happily moving on to his or her next research interest, pursuing a completely new design. Those of us stuck in the "real world" of trying to make a living with our software skills are a different matter.
In my experience, once having worked with Lisp I found it extremely difficult to switch to programming in Java. I spent a lot of time trying to make Java look like Lisp, which in my opinion made my code more readable, but to other programmers I worked with - not so much. My point is, Lisp can be a mind altering experience, much like LSD (I suppose). Some have the ability to compartmentalize the experience and move on with other pursuits and some are forever hooked on the "forbitten" fruit.