IME it's not uncommon for women not to know their pension situation - maybe men too, but it was women I came across on the Back To 60 webpages. Some of the stories are heartbreaking.
It's easy for those who have had professional jobs or who keep abreast of the news and current affairs to assume that everyone else does likewise, but many people just don't. A significant number of women gave up jobs at 60, expecting to get a pension, and were then unable to get back into work when they realised their mistake.
I was aware that the pension age had risen, but genuinely have no idea of how I found out. I do know that I wasn't informed about the changes - I sent in a FOI request for all information held on me, and they did not send a letter to inform me of either change in the SPA.
I did read the financial pages in the days when we got newspapers, and I have always listened to programmes like Moneybox, so maybe I picked it up from there, but not everyone does, and it seems to me strange that anyone would assume just because they do things in a particular way that everyone else is stupid or ill-informed for not doing likewise.
I admit that it seems a bit odd not to look into all the ramifications before retiring - I knew to the penny what I would get and when -, but if someone has assumed that what they were told would happen would be honoured, and they'd seen their mothers and older sisters get a pension at 60, it's not stupid or incompetent that they'd believe it themselves, really.
Anyway, the OP hasn't said that she didn't know the SPA had risen - just that she hadn't attached importance to paying contributions. Not everyone does - it's not unusual for people not to pay in - particularly married women. The controversy seems to be the opinion that this is ok for some of the population to opt out, but when others do it they must be stupid.