Carolyn said: >I can't recall where in Nabokov's work he
(or one of his characters?) castigates a student who sees symbolism in the green
>leaves of trees because "green is the color of hope." (Pale
Fire?)
Your hunch is correct - it's John Shade, in Pale Fire, talking
about marking student's exam scripts -
"[…]there are certain trifles I do not forgive.’[…]‘Not
having to read the required book. Having read it like an idiot.
Looking in it for symbols; example: “The author uses the striking image green
leaves because green is the symbol of happiness and frustration.” (note to
line 172, p.126 of my Penguin edition)