In a passage from Proust where the character first falls in love with Gilberte, he explains how when he first saw her he was initially struck by her dark eyes, but when he went away he carried off with him the information that she was blond and so in his fancy he assumed she had blue eyes. Once his imagination got to work over the next few days he found himself in love with her blue eyes, blue eyes she has never possessed, did not possess and never would possess.
“Si elle n’avait pas eu des yeux aussi noirs… je n’aurais pas ete, comme je le fus, plus particulierement amoureux , en elle, de ses yeux bleus.”
(“If she had not had such dark eyes, I would never have been, as I was, so particularly in love with her blue eyes.”)
Proust. Du Cote de Chez Swann/Swann’s Way
What flimsy evidence do we cherish as basis for our deepest convictions?