The mind is a strange machine which can combine the materials offered to it in the most astonishing ways, but without materials from the external world it is powerless, and unlike the sausage machine it must seize its materials for itself, since events only become experiences through the interest that we take in them: if they do not interest us, we are making nothing of them. The man, therefore, whose attention is turned within finds nothing worthy of his notice, ..
Source: The Conquest of Happiness, 1930, chap.11: Zest
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