From my journal, 24 April 1972:

I discovered today, by accident (browsing in a Shakespeare glossary), that "to be forsworn" can mean "to perjure oneself". This may shed light on a verse that to me is one of the most beautiful in English (from "The Cuckoo"):

If I am forsaken I'll not be forsworn,
And he's surely mistaken if he thinks that I'll mourn.
I'll get myself up in some right high degree
And pass as light by him as he can by me.

Most women, in particular, are moved by this; I wrote it in the notebook of a whore I met in a psychiatrist's office in New York, and the secretaries at Phys. Rev. preserved a sheet of paper I'd doodled it on in a meeting as an attempt at a new style of calligraphy. But what does the first line mean? My guess was "Just because he forsakes me I won't let the whole male sex swear off me", but that seems rather farfetched. Could it mean "...I won't pretend that my feelings are other than they are (i.e., relief)"? It's still pretty obscure.