The interesting thing about this (to me) is that he told me got into neuroscience because he suspected that something like the mechanism that generates diverse antibodies was operating in the nervous system to allow nerve cells to make connections with specific target cells.
A true giant in both immunology and neuroscience. Not only did he describe V(D)J recombination which allows for a huge number of antibodies to be made from relatively little DNA (and got a Nobel), but then pioneered the use of molecular approaches for understanding memory formation in the brain.