You're In Love, Charlie Brown [1967]
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Charlie Brown: It's stupid to just sit here and admire that little red haired girl from a distance. It's stupid not to get up and go over and talk to her.
Charlie Brown: It's really stupid! It's just plain stupid; so why I don't I go over and talk to her?!
Charlie Brown: Because I'm stupid.
Charlie Brown: There's nothing like unrequited love to take all the flavor out of a peanut butter sandwich.