Yes her husband was inattentive and non-responsive to her needs, but I didn't see any justification for her packing up and leaving.
I believe, in the book, she actually doesn't get into 'why' she left the M.
I haven't seen the movie and the book was good, as a summer read, but slightly contrived. I think one got the public, saleable version of her life at that time. I thought the part in India was the best.
Saffie me 46 H 46 M in 1986 D20,D18,S16,D13 H's A 01/05 to 07/06 H recommitted to M 07/06 renewed vows 09/06 Going from strength to strength
