Impossible, you say?
The human brain can and does (re)construct internal 3-dimensional worlds modeled on flat retinal images…
From Michael Bach’s ‘Optische Täuschung’ (Visual Illusions): “The upper contraption consists of the so-called “devil’s fork” (top right, also known as “blivet”), the “Penrose Frame” (centre) and the “hexnut” (3 of them at bottom left, an enlarged specimen at bottom right)—mind-boggling to envisage building such an object.”
M. C. Escher’s 1960 lithograph “Ascending and Descending” based on the Penrose stairs.