Rich says she thought things over during the summer holidays. But her predicament had been clearly preying on her mind long before that and intensified as the prospect of a Cabinet post loomed ever closer.
Watching her last year, something seemed amiss. Before Brash sacked her, she had been a stellar performer as National's welfare spokeswoman, producing a top-quality discussion document on welfare reform and exposing the infamous taxpayer-funded $26,000 worldwide hip-hop study tour.
Promoted by Key into the shadow education role, her performance was patchy. While she scored hits on Labour, she had periods when she was invisible. Rich's contribution to the front-bench forum at last year's National Party conference displayed a worrying lack of fresh policy direction.
No-one put the hard word on her to lift her game, however. She has too much respect in the National caucus for that to happen. Instead she put the hard word on herself.
Her decision is clearly the correct one - both for her and her party.
It is understood Key and his deputy, Bill English, made efforts to talk her out of leaving, but without much expectation of success.
Her walking away is the ultimate act of loyalty - one that guarantees Rich the lasting affection of the party she has so faithfully served.
