Part of the answer is that he taught himself to see differently. A somewhat overwrought and wordy Ph.D. thesis by a man named Gregory Galligan attempts to explain:
"Cézanne taught himself to see otherwise, that is, he mastered an ability to largely disregard his usual habits of stereometric perception for something far more fundamentally (in the ontological sense of the term) pictorial, or "painterly." Albert E. Gallatin understood this aesthetic implicitly when, on a routine visit to the Galleries Berneim-Jeune, Paris, in the summer of 1924, he purchased Cézanne's late watercolor, The Balcony, of 1900. In this instance, a wrought-iron window railing answers the implied arabesques of a distant view of brush and foliage—nature and culture thus taking part in a close poker of mutual bluffing.