Kevan Martin's obituary of neuroscientist Vernon Mountcastle (Nature 518, 304; 2015) nicely conveys the intensity of his passion for experimental work. This was eloquently expressed in a letter he sent to me on his retirement from the bench.

Mountcastle wrote: “I miss laboratory work in a way that is difficult to describe. It has always been my heart's joy, and my own experience has always been that even the most trivial original discovery of one's own evokes a special kind of ecstasy — it is almost like falling in love for the first time, all over again!”