Once a female, always a female. Nature is not always infallible but she always abides by her mistakes.
We all know the leopard can't change his stripes.
You cannot change the stripes of a leopard.
The Ethiopian cannot change his skin nor the leopard his spots.
History distinguishes what is accidental and transitory in human nature from what is essential and immutable.
The bottom line in both cases is that people don't change; that no matter how charming you are and how fiercely you love, you cannot turn a person into something she's not.
To have defined and sure opinions, fixed and known instincts, passions and character - all that is the horror of turning our soul into a fact, materialize it and make it external.