An interesting & unusual perspective.
Though I'd heard it referenced often, I didn't see Psycho until the late seventies. By then the ending was no surprise—it had been used, copied so often. I felt a bit let down.
But Psycho is one of those films, like Casablanca, that I enjoy more & more each time I see it. Much as I admire Vertigo & North By Northwest, I really like Psycho. It unfolds with a familiar, well-worn texture, that nevertheless continues to surprise with its adroitness & clarity.
While I quibble at Citizen Kane's position at number one on the AFI list, I certainly don't have any problem with Psycho's inclusion in the top ten.