After he was diagnosed with the illness that was to end his life, "on the last lap", as he expressed it, his family organised a screening of a film for which he had co-written the script, Reach for Glory (1962).
Malcolm Gladwell expresses it in his recent book Outliers: The Story of Success, as practice, practice, practice.
These poems, known as the "terrible sonnets," reveal strong tensions between his delight in the sensuous world and his urge to express it and his equally powerful sense of religious vocation.
As he expressed it on his website, he tried all his life "to do things I enjoy and feel are worth doing, and avoid doing everything else".
Monitoring the progress of his own sea change, Leon determines then to express it in his own book, "La Modification".
He never in his life thought of concealing what was either childlikeness or schizophrenia, and blithely expressed it in his art.
"I guess some people can find ways to express it," quipped his bandmate Steven Page.
He expressed it as his firm conviction that the popular welfare depends on the granting of what the great mass of the people want and need.
Yan remembers feeling, before he had the words to express it, that his hunger was an appendage, a huge tormenting tail that you couldn't cut off.
"It's like a miracle; that's the only way I can express it," said his mother, Olivia Hammar, who lives in Florida.
