A couple of posters really sticking the boot in to OP on this thread. In modern life, a perfectly normal average human being, with a normal average human brain that evolved to do hunter gatherer things, is expected to remember dozens of important but infrequent tasks with no apparent intrinsic saliency at arbitrary points, and have often been in effect trained to rely on things happening a certain way (reminders, auto-renewal) so they don't get forgotten.
Multiple insurance policies, multiple maintenance things, multiple licences, multiple health-related things, multiple payments and fees and subscriptions and installments, and each one treated as though it's the only thing you might have to remember. It's too much for a lot of us.
Difficult life events, mental illnesses like a bout of depression, a house move, differences like dyslexia, ADHD, ASD, lower than average IQ, early stages of dementia, or poor education, or a lost diary or phone or problem with an online calendar service (e.g. getting locked out of your Google account)… there are so many things that can make these expectations unrealistic, or which can put a spanner into even a smoothly-running system
We went several months without realising we had no home insurance. No idea why it didn't auto-renew like usual — I think it might've been because the bank decided to switch from MasterCard to Visa several years before the card used on the insurance account was due to expire, so the insurance company didn't know to contact us about an expired card but the payment didn't go through. That bank card switch messed up a lot of things. And DP was in trouble for defrauding the NHS once, because his prescription prepayment certificate ran out without him realising, and he hadn't received the usual reminder. And yes I suppose he should've put his own reminder on a calendar, but being a fallible human being, he'd got used to being sent one.
I know that it would've been horrendous for anyone who OP had hit while uninsured, and for OP herself, but I'd think she knows this and doesn't need berating any further. The system shouldn't rely on nobody ever messing up. We're just human and the expectations are difficult for many of us.