Pierre Kocher (1923–2005), aka Pilou, was born in Lausanne (Switzerland). As a person with a severe mental disability, he was committed to an institution at the age of eight. Refusing to speak, he communicated with others exclusively through gestures and gazes. Of a reserved, fearful and solitary nature, he structured his life through rituals that mattered greatly to him. He always took the same path from one point to another, always arranged his work in the same manner and carried out his everyday life gestures along the lines of a strict chronology he himself had set up.

His graphic output also reflects such repetitions. For over fifty years, Pilou would draw figures with cursory legs and round, empty eyes. Unfailingly, he would shape all his figures in the same way, beginning with a point and continuing the line in a chosen direction.  He would draw the outlines in pencil, with no hesitation, and without ever erasing a line.  He worked quickly, filling his shapes with generous swaths of color, without any changes or layering.

Encouraged by the teachers and caretakers, as of the 1980s "Pilou" began making drawings of a highly varied nature: abstract motifs, interpretations of famous works, portraits... while continuing to use crayons, which he would apply purely onto well demarcated surfaces.