It's bad to hate the opposite gender.
Jill was badly physically abused by her last ex-boyfriend.
Jill wants to make sure she's never hurt by a man again.
Jill becomes a nun and rarely leaves her nunnery.
Jill starts ranting at every man she meets about how they're all rapists.
After years of prayer and meditation, Jill is much less impacted by her trauma.
Jill is effectively unable to work, since pretty much every job has male employees or customers.