I'm really loving these old clips from The Dick Cavett Show on YouTube. Here's a 5-minute clip of Paul Simon telling Cavett about his music making process, his involvement in The Graduate, and how he wrote "Mrs. Robinson."
This is as good a time as any to share a theory about The Graduate that my late friend Mike Vodneck told me his high school teacher had about why Mrs. Robinson was willing to destroy her marriage to keep Ben from dating her daughter, Elaine. It's because Ben and Elaine were half-siblings. Try watching the movie with that in mind and see how it holds up.