My first contact with Stiefel occurred in 1943 when I was a 17 year old high school pupil. In November 1942 the then new art journal "Du" published an article about a way of cutting up a cube found by the prolific Swiss inventor Paul Schatz. I was so fascinated by this body which could be turned inside out that I constructed a cardboard model of it. My Hungarian mother who was then the physician of the Stiefel family showed this model to him who borrowed it in order to display it in his seminar on topology. I met him then for the first time personally when I got it back.