Rainer Joswig is similarly legendary for Common Lisp. I once thought a good way to really learn the language would be to answer some Stack Overflow questions.

Rainer Joswig is similarly legendary for Common Lisp. I once thought a good way to really learn the language would be to answer some Stack Overflow questions. Not once have I managed to get to a question that he hasn't already answered - and in much more detail than I ever could.