Well, I never said he’d written ‘Don’t Think Twice’, and as for plagiarism, yes many of his early songs are rewrites of other songs or melodies (eg Fare Thee Well, Hollis Brown, Hard Rain, Girl From the North Country, Ballad in Plain D, Farewell Angelina, Bob Dylan’s Dream, Song to Woody, Masters of War, and even Blowing in the Wind). The chord sequence to ‘Twice’, and it’s implied melody, is a standard ragtime song pattern, which I agree can be traced back beyond Paul Clayton to black blues songsters.